Change search
Refine search result
12 51 - 78 of 78
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 51.
    Mahade, Satyapal
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Li, Ran
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Curry, Nicholas
    Treibacher Industrie AG, Althofen, Austria.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Nylén, Per
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Isothermal Oxidation Behavior of Gd2Zr2O7/YSZ Multilayered Thermal Barrier Coatings2016In: International Journal of Applied Ceramic Technology, ISSN 1546-542X, Vol. 13, no 3, p. 443-450Article in journal (Refereed)
    Abstract [en]

    Efficiency of a gas turbine can be increased by increasing the operating temperature. Yttria-stabilized zirconia (YSZ) is the standard thermal barrier coating (TBC) material used in gas turbine applications. However, above 1200°C, YSZ undergoes significant sintering and CMAS (calcium magnesium alumino silicate) infiltration. New ceramic materials of rare earth zirconate composition such as gadolinium zirconate (GZ) are promising candidates for thermal barrier coating applications (TBC) above 1200°C. Suspension plasma spray of single-layer YSZ, double-layer GZ/YSZ, and a triple-layer TBC comprising denser GZ on top of GZ/YSZ TBC was attempted. The overall coating thickness in all three TBCs was kept the same. Isothermal oxidation performance of the three TBCs along with bare substrate and bond-coated substrate was investigated for time intervals of 10 h, 50 h, and 100 h at 1150°C in air environment. Weight gain/loss analysis was carried out by sensitive weighing balance. Microstructural analysis was carried out using scanning electron microscopy (SEM). As-sprayed single-layer YSZ and double-layer GZ/YSZ showed columnar microstructure, whereas the denser layer in the triple-layer TBC was not columnar. Phase analysis of the top surface of as-sprayed TBCs was carried out using XRD. Porosity measurements were made by water intrusion method. In the weight gain analysis and SEM analysis, multilayered TBCs showed lower weight gain and lower TGO thickness compared to single-layer YSZ.

  • 52.
    Mahade, Satyapal
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Mulone, Antonio
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg (SWE).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Klement, U.
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg (SWE).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Investigating load-dependent wear behavior and degradation mechanisms in Cr3C2-NiCr coatings deposited by HVAF and HVOF2021In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 15, p. 4595-4609Article in journal (Refereed)
    Abstract [en]

    Wear resistant coatings that comply with non-toxic environment goals are highly desirable. Cr3C2–NiCr is a promising alternative to the toxic, ‘Co’- containing WC–Co coatings to mitigate wear. The purpose of this study was to examine the suitability of Cr3C2–NiCr coatings for automotive brake disc application by systematically investigating their dry sliding wear behavior at different test conditions. Therefore, High Velocity Air Fuel (HVAF) and High Velocity Oxy Fuel (HVOF) were employed to deposit Cr3C2–NiCr coatings. The powder feedstock and as-deposited Cr3C2–NiCr coatings were characterized for their microstructure and phase composition using SEM and XRD. Mechanical properties (hardness, fracture toughness), porosity and surface topography of the as-deposited coatings were evaluated. The coatings were subjected to sliding wear tests at different normal loads (5 N, 10 N and 15 N) using alumina ball as the counter surface. Coefficient of friction (CoF) evolution of HVAF and HVOF deposited coatings, along with their wear performance, was obtained for different normal load conditions. The wear performance ranking of HVAF and HVOF processed coatings was influenced by the test conditions, with HVAF coatings demonstrating better wear resistance than HVOF coatings at harsh test conditions and the HVOF coatings performing better under mild wear test conditions. Detailed post-wear analysis of worn coatings, the alumina ball counter-body and the resulting debris was performed to reveal the degradation mechanisms at different test conditions. Findings from this work provide new insights into the desirable microstructural features to mitigate wear, which can be further exploited to deposit wear-resistant coatings.

    Download full text (pdf)
    JMR& T
  • 53.
    Mahade, Satyapal
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Mulone, Antonio
    University of Chalmers, Göteborg.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Klement, Uta
    University of Chalmers, Göteborg.
    Joshi, Shrikant
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Novel suspension route to incorporate graphene nano-platelets in HVAF-sprayed Cr3C2–NiCr coatings for superior wear performance2021In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 13, p. 498-512Article in journal (Refereed)
    Abstract [en]

    Graphene nano platelets (GNP) have several attractive properties, including excellent lubricity that can be used to develop wear-resistant coatings. Thermally sprayed chromium carbide–nickel chromium (Cr3C2–NiCr) coatings are widely employed to impart wear resistance to engineering components. This work attempts to improve the wear resistance of high velocity air fuel (HVAF) sprayed Cr3C2–NiCr coatings by incorporating GNP using a hybrid approach in which Cr3C2–NiCr (powder) and GNP (suspension) are co-axially injected. Two different powder-to-suspension delivery ratios were employed in this study that utilizes a liquid feedstock in tandem with a HVAF system. Furthermore, for comparison, a pure (without graphene) Cr3C2–NiCr reference coating was deposited by the HVAF process using identical spray parameters. The as-sprayed coatings were characterized for their microstructure and phase constitution by SEM/EDS and X-Ray Diffraction. Mechanical properties such as hardness and fracture toughness were evaluated using micro-indentation technique. The hybrid coatings were subjected to dry sliding wear tests and wear performance was compared with reference Cr3C2–NiCr. The GNP incorporated hybrid coatings exhibited lower CoF and lower wear rates than the reference Cr3C2–NiCr coating. Post wear SEM/EDS analysis revealed different wear mechanisms predominant in the investigated coatings. Utilizing the above as a case study, this work provides key insights into a new approach to produce GNP incorporated coatings for mitigating wear.

    Download full text (pdf)
    fulltext
  • 54.
    Mahade, Satyapal
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Mulone, Antonio
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg (SWE).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Klement, Uta
    Department of Industrial and Materials Science, Chalmers University of Technology, Gothenburg (SWE).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Incorporation of graphene nano platelets in suspension plasma sprayed alumina coatings for improved tribological properties2021In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 570, article id 151227Article in journal (Refereed)
    Abstract [en]

    Graphene possesses high fracture toughness and excellent lubrication properties, which can be exploited to enhance tribological performance of coating systems utilized to combat wear. In this work, suspension plasma spray (SPS) process was employed to deposit a composite, graphene nano-platelets (GNP) incorporated alumina coating. For comparison, monolithic alumina was also deposited utilizing identical spray conditions. The as-deposited coatings were characterized in detail for their microstructure, porosity content, hardness, fracture toughness and phase composition. Raman analysis of the as-deposited composite coating confirmed retention of GNP. The composite coating also showed good microstructural integrity, comparable porosity, higher fracture toughness and similar alumina phase composition as the monolithic alumina coating. The as-deposited coatings were subjected to dry sliding wear tests. The GNP incorporated composite coating showed lower CoF and lower specific wear rate than the pure alumina coating. Additionally, the counter surface also showed a lower wear rate in case of the composite coating. Post-wear analysis performed by SEM/EDS showed differences in the coating wear track and in the ball wear track of monolithic and composite coatings. Furthermore, Raman analysis in the wear track of composite coating confirmed the presence of GNP. The micro-indentation and wear test results indicate that the presence of GNP in the composite coating aided in improving fracture toughness, lowering CoF and specific wear rate compared to the monolithic coating. Results from this work demonstrated retention of GNP in an SPS processed coating, which can be further exploited to design superior wear-resistant coatings. 

    Download full text (pdf)
    Applied Surface Science
  • 55.
    Mahade, Satyapal
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Narayan, Karthik
    University West, Department of Engineering Science.
    Govindarajan, Sivakumar
    International Advanced Research Center for Powder Metallurgy and New Materials, Hyderabad 500069, India.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Curry, Nicholas
    Treibacher Industrie AG, 9330 Althofen, Austria.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Exploiting Suspension Plasma Spraying to Deposit Wear-Resistant Carbide Coatings.2019In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 15, article id E2344Article in journal (Refereed)
    Abstract [en]

    Titanium- and chromium-based carbides are attractive coating materials to impart wear resistance. Suspension plasma spraying (SPS) is a relatively new thermal spray process which has shown a facile ability to use sub-micron and nano-sized feedstock to deposit high-performance coatings. The specific novelty of this work lies in the processing of fine-sized titanium and chromium carbides (TiC and Cr3C2) in the form of aqueous suspensions to fabricate wear-resistant coatings by SPS. The resulting coatings were characterized by surface morphology, microstructure, phase constitution, and micro-hardness. The abrasive, erosive, and sliding wear performance of the SPS-processed TiC and Cr3C2 coatings was also evaluated. The results amply demonstrate that SPS is a promising route to manufacture superior wear-resistant carbide-based coatings with minimal in situ oxidation during their processing.

    Download full text (pdf)
    fulltext
  • 56.
    Mahade, Satyapal
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Ruelle, Céline
    ENSIL, Limoges, Franc.
    Curry, Nicholas
    Treibacher Industrie AG, Althofen, Austria.
    Holmberg, Jonas
    Swerea IVF AB, Mölndal, Sweden.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Nylén, Per
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Understanding the effect of material composition and microstructural design on the erosion behavior of plasma sprayed thermal barrier coatings2019In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 488, p. 170-184Article in journal (Refereed)
    Abstract [en]

    In this work, three different TBC compositions comprising of yttria partially stabilized zirconia (8YSZ), yttria fully stabilized zirconia (48YSZ) and gadolinium zirconate (GZ) respectively, were processed by suspension plasma spray (SPS) to obtain columnar microstructured TBCs. Additionally, for comparison, lamellar microstructured, 7YSZ TBC was deposited by air plasma spray (APS) process. SEM analysis was carried out to investigate the microstructure and white light interferometry was used to evaluate the surface morphology of the as-sprayed TBCs. Porosity measurements were made using water intrusion and image analysis methods and it was observed that the SPS-YSZ and APS-YSZ TBCs showed higher porosity content than SPS-GZ and SPS-48YSZ. The as-sprayed TBC variations (APS-YSZ, SPS-YSZ, SPS-GZ, and SPS-48YSZ) were subjected to erosion test. Results indicate that the erosion resistance of APS-YSZ TBC was inferior to the SPS-YSZ, SPS-GZ and SPS-48YSZ TBCs respectively. Among the SPS processed TBCs, SPS-YSZ showed the highest erosion resistance whereas the SPS-48YSZ showed the lowest erosion resistance. SEM analysis of the eroded TBCs (cross section and surface morphology) was performed to gain further insights on their erosion behavior. Based on the erosion results and post erosion SEM analysis, erosion mechanisms for splat like microstructured APS TBC and columnar microstructured SPS TBCs were proposed. The findings from this work provide new insights on the erosion mechanisms of columnar microstructured TBCs and lamellar microstructured TBCs deposited by plasma spray. © 2019 Elsevier B.V.

  • 57.
    Markocsan, Nicolaie
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Manitsas, Dimosthenis
    University West, Department of Engineering Science, Division of Welding Technology.
    Jiang, Janna
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    MAX-phase coatings produced by thermal spraying2017In: Journal of Superhard Materials, ISSN 1063-4576, Vol. 39, no 5, p. 355-364Article in journal (Refereed)
    Abstract [en]

    This paper presents a comparative study on the Ti2AlC coatings produced by different thermal spray methods, as Ti2AlC is one of the most studied materials from the MAX-phase family. Microstructural analysis of coatings produced by High Velocity Air Fuel (HVAF), Cold Spray and High Velocity Oxygen Fuel (HVOF) has been carried out by means of the scanning electron microscopy equipped with an energy dispersive spectrometer (EDS). The volume fraction of porosity was determined using the ASTM standard E562. The phase characterization of the as-received powder and as-sprayed coatings was conducted using the X-ray diffraction with CrKα radiation. Impact of the spray parameters on the porosity and the mechanical properties of the coatings are discussed. The results show that the spraying temperature and velocity play a crucial role in coatings characteristics. © 2017, Allerton Press, Inc.

  • 58.
    Markocsan, Nicolaie
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Manitsas, Dimosthenis
    University West, Department of Engineering Science, Research Enviroment Production Technology West. University West, Department of Engineering Science, Division of Welding Technology.
    Nicholas, Curry
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    MAX-phase coatings produced by thermal spraying2016In: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings: 25th – 27th of October 2016, Lund: Swedish Production Academy , 2016, p. 1-8Conference paper (Refereed)
    Abstract [en]

    This paper presents a comparative study on Ti2AlC coatings produced by different thermal spray methods, as Ti2AlC is one of the most studied materials from the MAX phase family. Microstructural analysis on coatings produced by High Velocity Air Fuel (HVAF), Cold Spray and High Velocity Oxygen Fuel (HVOF) has been carried out by means of scanning electron microscopy equipped with energy dispersive spectrometer (EDS). The volume fraction of porosity was determined using the ASTM standard E562. The phase characterization of the as-received powder and the as-sprayed coatings was conducted using X-ray diffraction with Cr Kα radiation. Impact of spray parameters on the porosity and the mechanical properties of the coatings are also discussed. The results show that the spraying temperature and velocity plays a crucial role on coatings characteristics.

  • 59.
    Mathiyalagan, Sribalaji
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Rossetti, Matteo
    University West,Trolhättan (SWE); Università di Modena e Reggio Emilia, Moderna (ITA).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of mechanical engineering.
    Basu, Soudip
    Indian Institute of Technology Bombay, Mumbai (IND).
    Balila, Nagamani Jaya
    Indian Institute of Technology Bombay, Mumbai (IND).
    Sowers, Susanne
    Hyperion Materials & Technologies, Worthington, Ohio (USA).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of mechanical engineering.
    Deposition characteristics and tribological performance of atmospheric plasma sprayed diamond metal matrix composite (DMMC) coatings2024In: Materials Chemistry and Physics, ISSN 0254-0584, E-ISSN 1879-3312, Vol. 315Article in journal (Refereed)
    Abstract [en]

    Diamond-reinforced metal matrix composites (DMMC) have great potential for wear-resistance applications due to the superior hardness imparted by diamond. Atmospheric plasma spraying involving axial injection of suitable feedstock is a convenient pathway to fabricate DMMC coatings for tribological applications. In this paper, thick DMMC coatings were deposited by plasma spraying Ni–P clad diamond particles under varying spray conditions. It was found that the phase characteristics of DMMC coatings as well as extent of diamond retention and fragmentation were significantly influenced by spray conditions such as, stand-off distance (SOD) and carrier gas flow rate (CGFR). Mechanical characterization (by micro-indentation) on all DMMC coatings developed in this work showed that coatings sprayed with longer SOD and higher CGFR has relatively higher hardness than other two coatings. However, on nanoindentation, the diamond hardness was found overestimated due to effect of diamond roughness on fragmentation. Ball-on-disc wear testing showed excellent tribological properties in all cases, with enhanced wear performance being noted when more diamond is retained in the coating. © 2024

    Download full text (pdf)
    fulltext
  • 60.
    Mathiyalagan, Sribalaji
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Rossetti, Matteo
    University West, Department of Engineering Science. Universita di Modena e Reggio Emilia, Via Pietro Vivarelli 10/1, 41125 Modena (ITA).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Sowers, Susanne
    Hyperion Materials & Technologies, 43085 Worthington, Ohio (USA).
    Dumm, Timothy
    Hyperion Materials & Technologies, 43085 Worthington, Ohio (USA).
    Kim, Chung
    Hyperion Materials & Technologies, 43085 Worthington, Ohio (USA).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    High velocity air fuel (HVAF) spraying of nickel phosphorus-coated cubic-boron nitride powders for realizing high-performance tribological coatings2022In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 18, p. 59-74Article in journal (Refereed)
    Abstract [en]

    High velocity air fuel (HVAF) spraying is an emergent thermal spray process, which is used in this work to realize high-performance large area tribological coatings of nickel-phosphorus cladded cubic-boron nitride (c-BN) particles. To the best of authors’ knowledge, this is the first time that HVAF has been utilized for developing Ni–P coatings reinforced with c-BN (NBN). The importance of appropriate processing was highlighted by utilizing two different nozzle configurations, for which microstructure, phase analysis and hardness results demonstrates considerable differences. Furthermore, the coatings were subjected to sliding wear tests to assess their friction and wear characteristics. Post-wear SEM analysis reveals the associated wear mechanisms. Effect of annealing on tribological performance of NBN coatings was also examined, and it is shown that optimal processing can preclude the need for post-treatment. Results ensuing from this work lay the foundation for new generation of HVAF-sprayed wear resistant metal/c-BN composite coatings for diverse applications. © 2022 The Author(s)

    Download full text (pdf)
    fulltext
  • 61.
    Meghwal, Ashok
    et al.
    Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn (AUS).
    Anupam, Ameey
    Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn (AUS).
    Boschen, Michael
    Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn (AUS).
    Singh, Surinder
    Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn (AUS).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Munroe, Paul
    iversity West, Department of Engineering Science, Trollhattan, ¨ Sweden d Materials Science and Engineering, UNSW, Sydney (AUS).
    Berndt, Christopher C.
    Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn (AUS).
    Ang, Andrew Siao Ming
    Surface Engineering for Advanced Materials (SEAM), Swinburne University of Technology, Hawthorn (AUS).
    Novel Al2CoCrFeNi high-entropy alloy coating produced using suspension high velocity air fuel (SHVAF) spraying2023In: Intermetallics, ISSN 0966-9795, Vol. 163, p. 1-4, article id 108057Article in journal (Refereed)
    Abstract [en]

    Metallic coatings of Al2CoCrFeNi high entropy alloy (HEA) were deposited using the suspension high velocity air fuel spray (SHVAF) process, towards exploring its viability as a bond coat in thermal barrier coatings. The relatively high Al content promoted a BCC + B2 phase-dominated coating structure, leading to enhanced mechanical properties. The oxidized microstructure exhibited a protective Al2O3 layer with characteristics comparable to conventional bond coat alloys. 

    Download full text (pdf)
    fulltext
  • 62.
    Michalak, Monika
    et al.
    Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wrocław (POL).
    Sokolowski, Pawel
    Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wrocław (POL).
    Szala, Miroslaw
    Department of Materials Engineering, Faculty of Mechanical Engineering, Lublin University of Technology, Lublin (POL).
    Walczak, Mariusz
    Department of Materials Engineering, Faculty of Mechanical Engineering, Lublin University of Technology, Lublin (POL),.
    Latka, Leszek
    Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wrocław (POL).
    Toma, Filofteia-Laura
    Fraunhofer Institute for Material and Beam Technology IWS, Thermal Spraying Group, Dresden (DEU).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Wear Behavior Analysis of Al2O3 Coatings Manufactured by APS and HVOF Spraying Processes Using Powder and Suspension Feedstocks2021In: Coatings, ISSN 2079-6412, Vol. 11, no 8, article id 879Article in journal (Refereed)
    Abstract [en]

    Thermally sprayed ceramic coatings are applied for the protection of surfaces that are exposed mainly to wear, high temperatures, and corrosion. In recent years, great interest has been garnered by spray processes with submicrometric and nanometric feedstock materials, due to the refinement of the structure and improved coating properties. This paper compares the microstructure and tribological properties of alumina coatings sprayed using conventional atmospheric plasma spraying (APS), and various methods that use finely grained suspension feedstocks, namely, suspension plasma spraying (SPS) and suspension high-velocity oxy-fuel spraying (S-HVOF). Furthermore, the suspension plasma-sprayed Al2O3 coatings have been deposited with radial (SPS) and axial (A-SPS) feedstock injection. The results showed that all suspension-based coatings demonstrated much better wear resistance than the powder-sprayed ones. S-HVOF and axial suspension plasma spraying (A-SPS) allowed for the deposition of the most dense and homogeneous coatings. Dense-structured coatings with low porosity (4 vol.%) and good cohesion to the metallic substrate, containing a high content of alpha-Al2O3 phase (56 vol.%) and a very low wear rate (0.2 +/- 0.04 mm(3) x 10(-6)/(N center dot m)), were produced with the S-HVOF method. The wear mechanism of ceramic coatings included the adhesive wear mode supported by the fatigue-induced material delamination. Moreover, the presence of wear debris and tribofilm was confirmed. Finally, the coefficient of friction for the coatings was in the range between 0.44 and 0.68, with the highest values being recorded for APS sprayed coatings.

    Download full text (pdf)
    Coatings
  • 63.
    Mulone, Antonio
    et al.
    Chalmers University of Technology, Department of Industrial and Materials Science, Gothenburg (SWE).
    Mahade, Satyapal
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Lundström, Dennis
    GKN Aerospace Engines Sweden, Trollhättan (SWE).
    Kjellman, Björn
    GKN Aerospace Engines Sweden, Trollhättan (SWE).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Klement, Uta
    Chalmers University of Technology, Department of Industrial and Materials Science, Gothenburg (SWE).
    Development of yttria-stabilized zirconia and graphene coatings obtained by suspension plasma spraying: Thermal stability and influence on mechanical properties2023In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 49, no 6, p. 9000-9009Article in journal (Refereed)
    Abstract [en]

    This study investigated the feasibility of depositing graphene nanoplatelet (GNP)-reinforced yttria-stabilized zirconia (YSZ) composite coatings. The coatings were deposited from an ethanol-based mixed YSZ and GNP suspension using suspension plasma spraying (SPS). Raman spectroscopy confirmed the presence of GNPs in the YSZ matrix, and scanning electron microscopy (SEM) analysis revealed a desired columnar microstructure with GNPs distributed predominantly in the inter-columnar spacing of the YSZ matrix. The as-deposited YSZ-GNP coatings were subjected to different isothermal treatments—400, 500, and 600 °C for 8 h—to study the thermal stability of the GNPs in the composite coatings. Raman analysis showed the retention of GNPs in specimens exposed to temperatures up to 500 °C, although the defect concentration in the graphitic structure increased with increasing temperature. Only a marginal effect on the mechanical properties (i.e., hardness and fracture toughness) was observed for the isothermally treated coatings. 

    Download full text (pdf)
    fulltext
  • 64.
    Musalek, Radek
    et al.
    Department of Materials Engineering, Institute of Plasma Physics AS CR, v.v.i, Za Slovankou 3, 182 00, Praha 8, Czech Republic.
    Kovarik, Ondrej
    Czech Technical University in Prague, Department of Materials, Faculty of Nuclear Sciences and Physical Engineering, Trojanova 13, 120 00, Praha 2, Czech Republic.
    Medricky, Jan
    Czech Technical University in Prague, Department of Materials, Faculty of Nuclear Sciences and Physical Engineering, Trojanova 13, 120 00, Praha 2, Czech Republic.
    Curry, Nicholas
    University West, Department of Engineering Science, Division of Mechanical Engineering.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Nylén, Per
    University West, Department of Engineering Science, Division of Production Engineering.
    Fatigue Performance of TBC on Structural Steel Exposed to Cyclic Bending2014In: Proceedings of the International Thermal Spray Conference, ASM International, 2014, p. 880-885Conference paper (Refereed)
    Abstract [en]

    For applications with variable loading, fatigue performance of coated parts is of utmost importance. In this study, fatigue performance of conventional structural steel coated with thermal barrier coating (TBC) was evaluated in cyclic bending mode by "SF-Test" device. Testing was carried out for as-received and grit-blasted substrates, as well as for samples with Ni-based bond-coat and bond-coat with YSZ-based top-coat. Comparison of results obtained for different loading amplitudes supplemented by fractographic analysis enabled identification of dominating failure mechanisms and evaluation of fatigue resistance alteration due to the deposited coatings.

  • 65.
    Musalek, Radek
    et al.
    Institute of Plasma Physics AS CR, Department of Materials Engineering , v.v.i, Za Slovankou 3, 182 00, Praha 8, Czech Republic.
    Kovarik, Ondrej
    Czech Technical University in Prague, Department of Materials, Faculty of Nuclear Sciences and Physical Engineering, Trojanova 13, 120 00, Praha 2, Czech Republic.
    Medricky, Jan
    Czech Technical University in Prague, Department of Materials, Faculty of Nuclear Sciences and Physical Engineering, Trojanova 13, 120 00, Praha 2, Czech Republic.
    Curry, Nicholas
    University West, Department of Engineering Science, Division of Mechanical Engineering.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Nylén, Per
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Fatigue Testing of TBC on Structural Steel by Cyclic Bending2014In: Journal of thermal spray technology (Print), ISSN 1059-9630, E-ISSN 1544-1016, Vol. 24, no 1-2, p. 168-174Article in journal (Refereed)
    Abstract [en]

    For applications with variable loading, fatigue performance of coated parts is of utmost importance. In this study, fatigue performance of conventional structural steel coated with thermal barrier coating (TBC) was evaluated in cyclic bending mode by “SF-Test” device. Testing was carried out at each stage of the TBC preparation process, i. e., for as-received and grit-blasted substrates, as well as for samples with Ni-based bond-coat and complete TBC: bond-coat with YSZ-based top-coat. Comparison of results obtained for different loading amplitudes supplemented by fractographic analysis enabled identification of dominating failure mechanisms and demonstrated applicability of the high-frequency resonant bending test for evaluation of fatigue resistance alteration at each stage of the TBC deposition process.

  • 66.
    Musalek, Radek
    et al.
    Institute of Plasma Physics AS CR, Department of Materials Engineering, v.v.i..
    Kovarik, Ondrej
    Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Prague, Czech Republic.
    Tomek, Libor
    Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Prague, Czech Republic.
    Medricky, Jan
    Institute of Plasma Physics AS CR, Department of Materials Engineering, v.v.i..
    Pala, Zdenek
    Institute of Plasma Physics AS CR, Department of Materials Engineering, v.v.i..
    Hausild, Petr
    Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Department of Materials.
    Capek, Jiri
    Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Department of Solid State Engineering.
    Kolarik, Kamil
    Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Department of Solid State Engineering.
    Nicholas, Curry
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Fatigue Performance of TBCs on Hastelloy X Substrate During Cyclic Bending2016In: Journal of thermal spray technology (Print), ISSN 1059-9630, E-ISSN 1544-1016, Vol. 25, no 1-2, p. 231-243Article in journal (Refereed)
    Abstract [en]

    Our previous experiments with low-cost steel substrates confirmed that individual steps of conventional thermal barrier coating (TBC) deposition may influence fatigue properties of the coated samples differently. In the presented study, testing was carried out for TBC samples deposited on industrially more relevant Hastelloy X substrates. Samples were tested after each step of the TBC deposition process: as-received (non-coated), grit-blasted, bond-coated (NiCoCrAlY), and bond-coated + top-coated yttria-stabilized zirconia (YSZ). Conventional atmospheric plasma spraying (APS) was used for deposition of bond coat and top coat. In addition, for one half of the samples, dual-layer bond coat was prepared by combination of high-velocity air-fuel (HVAF) and APS processes. Samples were tested in the as-sprayed condition and after 100 hours annealing at 980 °C, which simulated application-relevant in-service conditions. Obtained results showed that each stage of the TBC manufacturing process as well as the simulated in-service heat exposure may significantly influence the fatigue properties of the TBC coated part. HVAF grit-blasting substantially increased the fatigue performance of the uncoated substrates. This beneficial effect was suppressed by deposition of APS bond coat but not by deposition of dual-layer HVAF + APS bond coat. All heat-treated samples showed again enhanced fatigue performance. © 2015 ASM International

  • 67.
    Musalek, Radek
    et al.
    Institute of Plasma Physics as CR, V.v.i., Prague, Czech Republic.
    Medricky, Jan
    Institute of Plasma Physics as CR, V.v.i., Prague, Czech Republic.
    Pala, Zdenek
    Institute of Plasma Physics as CR, V.v.i., Prague, Czech Republic.
    Kovarik, Ondrej
    Czech Technical University in Prague, Prague, Czech Republic.
    Tomek, Libor
    Czech Technical University in Prague, Prague, Czech Republic.
    Curry, Nicholas
    University West, Department of Engineering Science, Division of Mechanical Engineering.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Fatigue performance of TBCs on hastelioy X substrate during cyclic bending2015In: Thermal Spray 2015: Proceedings from the International Thermal Spray Conference (May 11–14, 2015, Long Beach, California, USA) / [ed] Agarwal A.,Lau Y.-C.,McDonald A.,Bolelli G.,Toma F.-L.,Concustell A.,Widener C.A.,Turunen, ASM International, 2015, Vol. 1, p. 406-412Conference paper (Refereed)
    Abstract [en]

    Our previous experiments with low-cost steel substrates confirmed that individual steps of conventional thermal barrier coating (TBC) deposition may influence fatigue properties of the coated samples differently. In this study, testing was carried out for TBC samples deposited on industrially more relevant Hastelioy X substrates. Samples were tested after each step of TBC deposition process: As-received (non- coated), grit-blasted, bond-coated (NiCoCrAlY) and bond- coated + top-coated (yttria-stabilized zirconia - YSZ). Conventional atmospheric plasma spraying (APS) with gas stabilized plasma torch was used for deposition of both bond coat and top coat. In addition, for one half of the samples, bond coat was prepared by consecutive combination of HVAF (High Velocity Air Fuel) and APS processes. Samples were tested both in as-sprayed condition and after 100 hours annealing at 980 °C, which simulated in-service conditions. Obtained results showed that different fatigue performance may be expected for various stages of the TBC deposition as well as due to the variation of the deposition process and sample temperature history. © Copyright (2015) by ASM International All rights reserved.

  • 68.
    Owoseni, Tunji A.
    et al.
    University West, Department of Engineering Science, Division of Production Systems. Kwara State University, Ilorin (NGA).
    Ciudad de Lara, Irene
    University West, Trollhättan (SWE).
    Mathiyalagan, Sribalaji
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Microstructure and Tribological Performance of HVAF-Sprayed Ti-6Al-4V Coatings2023In: Coatings, ISSN 2079-6412, Vol. 13, no 11, p. 1-15Article in journal (Refereed)
    Abstract [en]

    Ti-6Al-4V is a widely used titanium alloy in aviation and bio/chemical applications for its attractive mechanical and corrosion resistance properties. The use of Ti-6Al-4V as a coating for repair purposes through thermal spray techniques provides a unique productivity opportunity. A repair coating must be dense to provide the required in-service functionalities, such as resistance to wear. The High Velocity Air Fuel (HVAF) thermal spray technique deposits dense coatings with reduced concern for oxide inclusions. This work presents an investigation of the microstructure, dry sliding, and solid particle erosive wear performance of four different coatings engineered through the configuration of the nozzle of an HVAF spray gun, based on the length of the nozzle and the size of the nozzle exit. A long nozzle length and wide nozzle exit mean increased inflight dwell time and reduced average inflight temperature for the sprayed particles, respectively—a reversed configuration means the opposite. The tested coatings showed a porosity of less than 2%. The sliding and erosion wear performance of the densest of the coatings compares to that of the bulk material tested under the same conditions. Electron microscopy was used to investigate the driving mechanisms for the performance of the respective coatings. The implications of the results are discussed for the potential adoption of HVAF-sprayed coatings in metal component repair.

    Download full text (pdf)
    fulltext
  • 69.
    Rossetti, Matteo
    et al.
    Dipartimento di Ingegneria “Enzo Ferrari”, Università di Modena e Reggio Emilia, Modena (ITA).
    Mathiyalagan, Sribalaji
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Sowers, Sussane
    Hyperion Materials & Technologies, Worthington,Ohio (USA).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Advanced diamond-reinforced metal matrix composite (DMMC) coatings via HVAF process: Effect of particle size and nozzle characteristics on tribological properties2023In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 49, no 11 Part A, p. 17838-17850Article in journal (Refereed)
    Abstract [en]

    High-velocity air fuel (HVAF) spraying is a versatile and cost-effective platform to fabricate wear resistant coatings. In this work, deposition of Nickel–Phosphorus cladded diamond feedstock is explored as a greener alternative to realize highly wear resistant large-area coatings. To the best of authors knowledge. this is the first study that has utilized HVAF technique for developing wear resistant Ni–P coatings reinforced with diamond (NCD). This work also aims to understand the effect of particle size by using coarse (20–30 μm) and fine NCD (10–15 μm) particles as feedstock. The importance of utilizing appropriate processing conditions was also highlighted by using two different nozzle configurations, for which the two powder particle sizes exhibited considerable differences in terms of microstructure, phase characteristics and mechanical properties. Further, the effect of annealing on the above coating characteristics was also examined, and it is shown that optimal spraying conditions can preclude the need for post-treatment. Furthermore, the as-deposited and annealed coatings were subjected to sliding wear tests to assess their tribological performance. Post-wear analysis performed on worn surfaces revealed the associated wear mechanisms. The results ensuing from this work lay the foundation for realizing new generation of HVAF sprayed wear resistant Ni–P/diamond composite coatings for diverse applications.

  • 70.
    Sadeghimeresht, Esmaeil
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Nylén, Per
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Bi-layer thermal spray coatings: A critical approach to extend the service-life of metallic components2016Conference paper (Other academic)
  • 71.
    Sadeghimeresht, Esmaeil
    et al.
    University West, Department of Engineering Science, Research Environment Production Technology West. Amirkabir University of Tehran, Tarbiat Modares University of Tehran.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Manufacturing Processes.
    Nylén, Per
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Mechanical Engineering.
    Corrosion performance of bi-layer Ni/Cr2C3–NiCr HVAF thermal spray coating2016In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 369, p. 470-481Article, review/survey (Refereed)
    Abstract [en]

    The corrosion behavior of three HVAF thermal spray coating systems (A: single-layer Ni, B: single-layer Cr2C3–NiCr coatings, and C: bi-layer Ni/Cr2C3–NiCr coating) was comparatively studied using immersion,salt spray, and electrochemical tests. Polarization and EIS results showed that the corrosion behavior of Cr2C3–NiCr coatings in 3.5 wt.% NaCl solution was significantly improved by adding the intermediate layer of Ni. It was illustrated that the polarization resistance of the bi-layer Ni/Cr2C3–NiCr and singlelayerCr2C3–NiCr coatings were around 194 and 38 k cm2, respectively. Microstructure analysis revealed that the bond coating successfully prevented the corrosion propagation toward the coating.

  • 72.
    Silveira, L. L.
    et al.
    Federal University of Technology - Parana, Post-graduate Program in Mechanical Engineering, Ponta Grossa, PR, Brazil.
    Pukasiewicz, A. G. M.
    Federal University of Technology - Parana, Post-graduate Program in Mechanical Engineering, Ponta Grossa, PR, Brazil.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Nylén, Per
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Zara, A. J.
    State University of Ponta Grossa, Ponta Grossa, PR, Brazil.
    Comparative Study of the Corrosion and Cavitation Resistance of HVOF and HVAF FeCrMnSiNi and FeCrMnSiB Coatings2017In: Proceedings of the International Thermal Spray Conference & Exposition (ITSC 2017), New York: Curran Associates, Inc , 2017, Vol. 2, p. 675-680Conference paper (Refereed)
    Abstract [en]

    Cavitation and corrosion on hydrodynamic components and systems reduces the operational efficiency. The use of wear resistant coatings have been studied as a solution to the problem of corrosion and cavitation in the industrial environment. Thermal spray processes are recognized as excellent technique to deposit coatings. The high velocity oxy-fuel process (HVOF) can produce high density and bond strength coatings. High velocity air-fuel process (HVAF) is an alternative process, shown to be superior regarding corrosion protection and production costs. HVAF can deposit coating with shorter dwell time and lower temperature, producing coating with lower oxide content This paper presents the use of HVOF and HVAF process to deposit FeCrMnSiNi and FeCrMnSiB coatings, studying the resistance against corrosion and cavitation in comparison to 316L HVOF coating. Microstructure was analyzed by XRD, microscopic means and mechanical testing. Cavitation and corrosion behavior of the coatings were also studied comparatively. HVAF coatings presented lower porosity and oxide levels, as well as higher hardness values, compared with the coatings deposited by HVOF process. The HVAF process presented better cavitation resistance than HVOF coatings. The FeCrMnSiNi HVAF coating had the best corrosion protection performance between the developed alloys. 

  • 73.
    Silveira, L. L.
    et al.
    UTFPR – Universidade Tecnológica Federal do Paraná, Post-graduate Program in Mechanical Engineering, Ponta Grossa, PR 84016-210, Brazil.
    Pukasiewicz, A. G. M.
    UTFPR – Universidade Tecnológica Federal do Paraná, Post-graduate Program in Mechanical Engineering, Ponta Grossa, PR 84016-210, Brazil.
    de Aguiar, D. J. M.
    UTFPR – Universidade Tecnológica Federal do Paraná, Post-graduate Program in Mechanical Engineering, Ponta Grossa, PR 84016-210, Brazil.
    Zara, A. J.
    UEPG – Universidade Estadual de Ponta Grossa, Ponta Grossa, PR 84010-330, Brazil.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Study of the corrosion and cavitation resistance of HVOF and HVAF FeCrMnSiNi and FeCrMnSiB coatings2019In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 374, p. 910-922Article in journal (Refereed)
    Abstract [en]

    Cavitation and corrosion on hydrodynamic components and systems reduces the operational efficiency. The use of wear resistant coatings has been studied as a solution to the problem of corrosion and cavitation in industrial environments. The high velocity oxy-fuel process (HVOF) can produce coatings with high density and bond strength. High velocity air-fuel (HVAF) is an alternative process, which can deposit coatings with higher velocity and lower temperatures, compared to the HVOF process, resulting in lower oxide content. This paper analyzes the HVOF and HVAF processes to deposit FeCrMnSiNi and FeCrMnSiB coatings, comparing their cavitation and corrosion resistance. HVAF coatings presented lower porosity and oxide levels, as well as higher hardness values. The HVAF process presented better cavitation and corrosion resistance, due to lower porosity and oxide contents of the coatings. The amount of oxides and pores in the coatings was crucial in their corrosive behavior, by facilitating the penetration of the chloride ions through the pores, leading to a higher corrosion rate and pitting formation. © 2019 Elsevier B.V.

  • 74.
    Sokolowski, Pawel
    et al.
    Wroclaw Univ Sci & Technol, Fac Mech Engn, Ul Lukasiewicza 5, PL-50371 Wroclaw, Poland.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Manufacturing Processes. University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Musalek, Radek
    Inst Plasma Phys CAS, Dept Mat Engn, Vvi, Slovankou 3, Prague 18200, Czech Republi.
    Candidato, Rolando T. Jr.
    Univ Limoges, Lab SPCTS, UMR CNRS 7315, 12 Rue Atlantis, F-87068 Limoges, France.
    Pawlowski, Lech
    Univ Limoges, Lab SPCTS, UMR CNRS 7315, 12 Rue Atlantis, F-87068 Limoges, Fran.
    Nait-Ali, Benoit
    Univ Limoges, Lab SPCTS, UMR CNRS 7315, 12 Rue Atlantis, F-87068 Limoges, Fran.
    Smith, David
    Univ Limoges, Lab SPCTS, UMR CNRS 7315, 12 Rue Atlantis, F-87068 Limoges, Fran.
    Thermophysical properties of YSZ and YCeSZ suspension plasma sprayed coatings having different microstructures2017In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 318, p. 28-38Article in journal (Refereed)
    Abstract [en]

    The paper describes the ceramic top coats of Thermal Barrier Coatings (TBC) obtained by Suspension Plasma Spraying (SPS). The spray process realized with different plasma torches allowed obtaining coatings having different morphology, namely, columnar-like and two-zones microstructure. The microstructures influenced the thermal transport properties of TBC’s. The study analyses the thermophysical properties of yttria and yttria- with ceria- stabilized zirconia coatings, i.e. YSZ and YCeSZ, respectively. The spray processes were realized with the use of three different plasma spray torches: (i) SG-100; (ii) Axial III and (iii) hybrid WSP one. The deposition parameters were designed for each plasma torch separately. The microstructure of coatings was then analyzed using Optical and Scanning Electron Microscopy i.e. OM and SEM, respectively. The thermophysical properties of the coatings such as density, specific heat and thermal dilatation were measured using gas pycnometry, calorimetry and dilatometry methods respectively. The collected data were used, together with thermal diffusivity found with the use of laser flash method, to calculate the thermal conductivity of the deposits. The thermal conductivities of coatings were in a range from 0.63 to 0.99 [W/m.K] for YSZ samples and between 0.82 and 1.37 [W/m.K] in the case of YCeSZ coatings. Thermal transport properties were found to be influenced by the coatings’ porosity and their microstructure. Finally, the thermal conductivity values were successfully validated using response function method, which can be an alternative to complex FEM methods. (C) 2017 Elsevier B.V. All rights reserved.

  • 75.
    Testa, Veronica
    et al.
    Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, MO, (ITA).
    Morelli, Stefania
    Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, MO, (ITA).
    Bolelli, Giovanni
    Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, MO, (ITA).
    Lusvarghi, Luca
    Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, MO, (ITA); National Interuniversity Consortium of Materials Science and Technology (INSTM), Local Unit, University of Modena and Reggio Emilia, Modena, MO, (ITA) ; nterMech – MO.RE, Centro Interdipartimentale per la Ricerca Applicata e i Servizi nel Settore della Meccanica Avanzata e della Motoristica, Università di Modena e Reggio Emilia, Modena, MO, (ITA).
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Micromechanical behaviour and wear resistance of hybrid plasma-sprayed TiC reinforced Tribaloy-4002021In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 425, article id 127682Article in journal (Refereed)
    Abstract [en]

    Cobalt-based alloys such as Tribaloy-400 are known for their sliding wear resistance at room as well as elevated temperature. However, further enhancement in terms of hardness and wear resistance could be achieved by creating metal matrix composites reinforced by ceramic particles. For this purpose, Tribaloy-400 based coatings were deposited with the addition of different amounts of TiC reinforcement (≈25 vol%, ≈40 vol%, ≈60 vol%) through a “hybrid” plasma spray process, using a dry Tribaloy-400 powder with 10–45 μm particle size and a water-based TiC suspension (d50 = 2.2 μm). Pure Tribaloy and pure TiC coatings were employed for comparison. During spraying, TiC was partly oxidized but could nonetheless be embedded between the bigger Tribaloy-400 lamellae. Specifically, the coating containing ≈ 25 vol% TiC shows a homogeneous microstructure, whilst greater amounts of hard phase lead to some agglomeration. Accordingly, the coating with 25 vol% TiC exhibits a good combination of hardness and toughness (the latter being assessed by scratch testing) and low sliding wear rates of ≈10−5–10−6 mm3/(N·m) from room temperature up to 700 °C in ball-on-disc tests against an Al2O3 counterbody. At room temperature, the tribological behaviour of the coatings is controlled by abrasive grooving and spallation due to surface fatigue. With increasing temperature, tribochemical phenomena take on an ever-increasing role and, at 700 °C, a uniform, oxide-based tribofilm is developed, so that the wear rates are often lower than are recorded at 400 °C.

  • 76.
    Torkashvand, Kaveh
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Gupta, Mohit Kumar
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Tribological Performance of Thin HVAF-Sprayed WC-CoCr Coatings Fabricated Employing Fine Powder Feedstock2023In: Journal of thermal spray technology (Print), ISSN 1059-9630, E-ISSN 1544-1016, Vol. 32, p. 1033-1046Article in journal (Refereed)
    Abstract [en]

    In this study, sliding and abrasion wear performance of WC-CoCr coatings deposited by high velocity air–fuel (HVAF) spraying with various thicknesses (i.e., 240, 150, 100, 50 and 30 µm), fabricated from fine feedstock powder (5–15 µm), were evaluated. The main aim was to investigate how thinner coatings (30 and 50 µm) perform compared to conventional thick coatings (> 100 µm), in an effort to address the supply and cost concerns associated with Co and W.

    The feedstock powder and deposited coatings were characterized in terms of microstructure. The hardness of the thin and thick coatings was measured using Vickers hardness method from both cross section and top-surface. It was found that, regardless of the thickness, extremely dense coatings with very high hardness ( 1500 HV) can be deposited employing HVAF and fine feedstock powder. Thin and thick coatings were found to perform similarly under sliding wear with a normal load of 10 N or lower as well as under abrasion wear conditions which highlights the possibility of employing thinner coatings for a majority of the real applications.

    The results suggest that peening effect does not have a considerable influence on the microstructure or performance of the deposited coatings. However, for sliding wear tests with a 20 N normal load, it was noticed that wear resistance of the coatings slightly declines with decreasing thickness of the coating beyond 150 µm. The main reason was identified to be the involvement of substrate effect when performing tests under severe Hertzian contact pressure.  

    Download full text (pdf)
    fulltext
  • 77.
    Torkashvand, Kaveh
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Gupta, Mohit Kumar
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Marra, Francesco
    Department of Chemical Engineering Materials Environment, Sapienza University of Rome (ITA).
    Baiamonte, Lidia
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. Department of Chemical Engineering Materials Environment, Sapienza University of Rome (ITA).
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Influence of nozzle configuration and particle size on characteristics and sliding wear behaviour of HVAF-sprayed WC-CoCr coatings2021In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 423, p. 127585-127585, article id 127585Article in journal (Refereed)
    Abstract [en]

    In this study, effect of feedstock particle size and nozzle configuration on deposition, microstructural features, hardness and sliding wear behaviour of high velocity air fuel (HVAF)-sprayed WC-CoCr coatings was evaluated. Three different WC-CoCr powders with nominal particle sizes of 5/20 μm (fine), 5/30 μm (medium) and 15/45 μm (coarse) were sprayed employing a HVAF gun with four distinct DeLaval nozzle configurations involving different lengths and/or exit diameters. Microstructure, phase constitution and mechanical characteristics of the coatings were evaluated using SEM, EDS, XRD and micro indentation testing. Specific wear rate for all the samples was determined under sliding conditions and a comprehensive post wear analysis was conducted. X-ray diffraction analysis showed negligible decarburization in all the HVAF-sprayed coatings. It was shown that decrease in particle size of employed feedstock results in discernible changes in microstructural features of the coatings as well as considerable improvement in their performance. Also, notable changes in wear mechanisms were identified on reducing particle size from coarse to medium or fine. Fine and coarse feedstock powders were found to be sensitive to the type of nozzle used while no major difference was observed in coatings from powders with medium cut size sprayed with different nozzles. 

  • 78.
    Torkashvand, Kaveh
    et al.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Gupta, Mohit Kumar
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Björklund, Stefan
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Marra, Francesco
    Department of Chemical Engineering Materials Environment, Sapienza University of Rome, Ita.
    Baiamonte, Lidia
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. Department of Chemical Engineering Materials Environment, Sapienza University of Rome, Ita.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Influence of nozzle configuration and particle size on characteristics and sliding wear behaviour of HVAF-sprayed WC-CoCr coatings2021In: Surface and Coatings Technology, ISSN 0257-8972, Vol. 423, p. 1-16, article id 127585Article in journal (Refereed)
    Abstract [en]

    In this study, effect of feedstock particle size and nozzle configuration on deposition, microstructural features, hardness and sliding wear behaviour of high velocity air fuel (HVAF)-sprayed WC-CoCr coatings was evaluated. Three different WC-CoCr powders with nominal particle sizes of 5/20 μm (fine), 5/30 μm (medium) and 15/45 μm (coarse) were sprayed employing a HVAF gun with four distinct DeLaval nozzle configurations involving different lengths and/or exit diameters. Microstructure, phase constitution and mechanical characteristics of the coatings were evaluated using SEM, EDS, XRD and micro indentation testing. Specific wear rate for all the samples was determined under sliding conditions and a comprehensive post wear analysis was conducted. X-ray diffraction analysis showed negligible decarburization in all the HVAF-sprayed coatings. It was shown that decrease in particle size of employed feedstock results in discernible changes in microstructural features of the coatings as well as considerable improvement in their performance. Also, notable changes in wear mechanisms were identified on reducing particle size from coarse to medium or fine. Fine and coarse feedstock powders were found to be sensitive to the type of nozzle used while no major difference was observed in coatings from powders with medium cut size sprayed with different nozzles.

    Download full text (pdf)
    fulltext
12 51 - 78 of 78
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf