Change search
Refine search result
3456 251 - 257 of 257
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.
  • 251.
    Venkatesh, L.
    et al.
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India. .
    Pitchuka, Suresh Babu
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India.
    Sivakumar, G.
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India.
    Gundakaram, Ravi C.
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Research Enviroment Production Technology West. University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Samajdar, I.
    Department of Metallurgical Engineering & Materials Science, IIT Bombay, Powai, Mumbai 400076, India.
    Microstructural response of various chromium carbide based coatings to erosion and nano impact testing2017In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 386-387, p. 72-79Article in journal (Refereed)
    Abstract [en]

    In this study, we demonstrate the microstructure dependency of erosion behaviour of laser clad, detonation sprayed and atmospheric plasma sprayed chromium carbide based coatings. The final chromium carbide content in all the coatings was a strong function of rapid solidification rate associated with the processes. In the laser clad coating majority of the chromium carbides re-solidified while in the thermally sprayed coatings chromium carbide re-solidification was hindered to a large extent. Hence, the final chromium carbide content in the thermally sprayed coating decreased with increased extent of particle melting during spraying. Decarburisation and oxidation during thermal spraying lead to the formation of chromium carbides with lower carbon content and chromium oxide(s). Laser clad and detonation sprayed coatings, with higher chromium carbide content, showed lower erosion rates and exhibited fewer brittle erosion events. Embrittlement due to excessive dissolution of chromium carbides into the matrix and poor splat bonding were found to be the reasons for higher erosion rate of the plasma sprayed coating. Scanning electron microscopy and quantification of single erodent impact events clearly established ductile material removal in the laser clad and detonation sprayed coating and brittle material removal in the plasma sprayed coating as the dominant mechanism(s). A good agreement was found between solid particle erosion testing and nano impact testing results.

  • 252. Venkatesh, L.
    et al.
    Samajdar, I.
    Tak, M.
    Gundakaram, R. C.
    Joshi, S. V.
    Process parameter impact on microstructure of laser clad inconel-chromium carbide layers2012In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 702-703, p. 963-966Article in journal (Refereed)
    Abstract [en]

    Chromium carbide based metal matrix composite (MMC) coatings are ideally suited for high temperature erosive-corrosive applications. Laser cladding of such MMCs, with Inconel as the ductile matrix instead of the usual NiCr alloy, has been attempted in the present study. The relative hardness of the laser clad layers was observed to drop with increase in laser power. The reduction in hardness was attributed to retention of lower amounts of chromium carbides in the clad layer at higher laser powers. Use of chemically assisted scans with electron diffraction allowed extraction of effective micro-textural information on the coatings. © (2012) Trans Tech Publications, Switzerland.

  • 253.
    Venkatesh, Lakshmi Narayanan
    et al.
    Int Adv Res Ctr Powder Met & New Mat ARCI, Hyderabad 500005, Andhra Pradesh, India.
    Babu, Pitchuka Suresh
    Int Adv Res Ctr Powder Met & New Mat ARCI, Hyderabad 500005, Andhra Pradesh, India.
    Gundakaram, Ravi Chandra
    Int Adv Res Ctr Powder Met & New Mat ARCI, Hyderabad 500005, Andhra Pradesh, India.
    Doherty, Roger D.
    Drexel Univ, Dept Mat Engn, Philadelphia, PA 19104 USA.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Samajdar, Indradev
    Indian Inst Technol, Dept Met Engn & Mat Sci, Mumbai 400076, Maharashtra, India.
    Morphology-Dependent Hardness of Cr7C3-Ni-Rich Alloy Composite vs Orientation Independent Hardness of Cr7C3 Primary Phase in a Laser Clad Microstructure2017In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 48A, no 4, p. 1534-1539Article in journal (Refereed)
    Abstract [en]

    Microstructural evolution with superheating was studied in chromium carbide-nickel coatings deposited by laser cladding. At lower superheating, selective growth of aOE (c) 0001 > direction from the high density of Cr7C3 grains nucleated resulted in a columnar structure with (0001) texture. Increased superheating lead to the loss of columnar structure as well as the (0001) texture. The hexagonal Cr7C3 showed an unusual isotropic nanoindentation hardness evidently correlated with its low c/a ratio. However, the rod-like morphology of the carbide dendrites resulted in significant anisotropy in the hardness of the composite.

  • 254.
    Venkatesh, Lakshmi Narayanan
    et al.
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India; Department of Metallurgical Engineering & Materials Science, IIT Bombay, Powai, Mumbai 400076, India.
    Venkataraman, B.
    Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad 500058, India.
    Tak, Manish
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India.
    Sivakumar, Ganapathy S.
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India.
    Gundakaram, Ravi C.
    International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur, Hyderabad 500005, India.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Samajdar, Indradev S.
    Department of Metallurgical Engineering & Materials Science, IIT Bombay, Powai, Mumbai 400076, India.
    Room temperature and 600 °C erosion behaviour of various chromium carbide composite coatings2019In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 422-423, p. 44-53Article in journal (Refereed)
    Abstract [en]

    In this study, the erosion behaviour of laser clad chromium carbide-Ni rich alloy composite coatings with a wide range of carbide contents at room temperature and 600 °C were investigated. The variation in carbide content of the coatings was due to dilution from the substrate and the high cooling rate in the laser cladding process preventing re-solidification of the molten carbides. Erosion rate was observed to be a function of carbide content alone and was significantly higher at 600 °C as compared to room temperature. Erosion wear ratio (E90/E30) was also dependent on carbide content but decreased at higher temperature and higher carbide contents. A comparison of erosion behaviour with detonation and plasma sprayed counterparts showed the superior performance of laser clad coatings at 600 °C. The poor erosion performance of the detonation and plasma sprayed coatings was due to weak splat bonding. Thick oxide layer formed on the steel substrate after pre-oxidation resulted in its poor erosion performance.

  • 255.
    Zafer, Yunus Emre
    et al.
    University West, Department of Engineering Science.
    Goel, Sneha
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Ganvir, Ashish
    Research & Technology, Department of Process Engineering, GKN Aerospace Engine Systems AB, 461 81 Trollhättan, Sweden.
    Jansson, Anton
    Örebro University, School of Science and Engineering, 701 82 Örebro, Sweden.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Encapsulation of Electron Beam Melting Produced Alloy 718 to Reduce Surface Connected Defects by Hot Isostatic Pressing2020In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 13, no 5, article id 1226Article in journal (Refereed)
    Abstract [en]

    Defects in electron beam melting (EBM) manufactured Alloy 718 are inevitable to some extent, and are of concern as they can degrade mechanical properties of the material. Therefore, EBM-manufactured Alloy 718 is typically subjected to post-treatment to improve the properties of the as-built material. Although hot isostatic pressing (HIPing) is usually employed to close the defects, it is widely known that HIPing cannot close open-to-surface defects. Therefore, in this work, a hypothesis is formulated that if the surface of the EBM-manufactured specimen is suitably coated to encapsulate the EBM-manufactured specimen, then HIPing can be effective in healing such surface-connected defects. The EBM-manufactured Alloy 718 specimens were coated by high-velocity air fuel (HVAF) spraying using Alloy 718 powder prior to HIPing to evaluate the above approach. X-ray computed tomography (XCT) analysis of the defects in the same coated sample before and after HIPing showed that some of the defects connected to the EBM specimen surface were effectively encapsulated by the coating, as they were closed after HIPing. However, some of these surface-connected defects were retained. The reason for such remnant defects is attributed to the presence of interconnected pathways between the ambient and the original as-built surface of the EBM specimen, as the specimens were not coated on all sides. These pathways were also exaggerated by the high surface roughness of the EBM material and could have provided an additional path for argon infiltration, apart from the uncoated sides, thereby hindering complete densification of the specimen during HIPing.

    Download full text (pdf)
    fulltext
  • 256.
    Zhang, Pimin
    et al.
    Linköping University, Department of Management and Engineering, Linköping, SE-58183, Sweden.
    Sadeghi, Esmaeil
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Chen, Shula
    Linköping University, Department of Physics, Chemistry, and Biology, Linköping, SE-58183, Sweden.
    Li, Xin-Hai
    Siemens Industrial Turbomachinery AB, Finspång, SE-61283, Sweden.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Joshi, Shrikant V.
    University West, Department of Engineering Science, Research Enviroment Production Technology West.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry, and Biology, Linköping, SE-58183, Sweden.
    Buyanova, Irina A.
    Linköping University, Department of Physics, Chemistry, and Biology, Linköping, SE-58183, Sweden.
    Peng, Ru L.in
    Linköping University, Department of Management and Engineering, Linköping, SE-58183, Sweden.
    Effects of surface finish on the initial oxidation of HVAF-sprayed NiCoCrAlY coatings2019In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 364, p. 43-56Article in journal (Refereed)
    Abstract [en]

    Oxide scale formed on HVAF-sprayed NiCoCrAlY coatings and the effect of surface treatment were investigated by a multi-approach study combining photo-stimulated luminescence, microstructural observation and mass gain. The initial oxidationbehaviour of as-sprayed, polished and shot-peened coatings at 1000 °C is studied. Both polished and shot-peened coatings exhibited superior performance due to rapid formation of α-Al2O3 fully covering the coating and suppressing the growth of transient alumina, assisted by a high density of α-Al2O3 nuclei on surface treatment induced defects. Moreover, the fast development of a two-layer alumina scale consisting of an inward-grown inner α-Al2O3 layer and an outer layer transformed from outward-grown transient alumina resulted in a higher oxide growth rate of the as-sprayed coating.

  • 257.
    Zhang, Pimin
    et al.
    Linköping University, Department of Management and Engineering, Linköping, Sweden.
    Sadeghimeresht, Esmaeil
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Peng, Ru Lin
    Linköping University, Department of Management and Engineering, Linköping, Sweden.
    Li, Xin-Hai
    Siemens Industrial Turbomachinery AB, Finspång, Sweden.
    Markocsan, Nicolaie
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Joshi, Shrikant
    University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing.
    Johansson, Sten
    Linköping University, Department of Management and Engineering, Linköping, Sweden.
    Isothermal oxidation behavior of HVAF-sprayed NiCoCrAlY coatings: Effect of surface treatment2017In: Proceedings of the International Thermal Spray Conference & Exposition (ITSC 2017), New York: Curran Associates, Inc , 2017, Vol. 1, p. 456-461Conference paper (Refereed)
    Abstract [en]

    NiCoCrAlY coatings are widely used as bond coats for ceramic thermal barrier coatings (TBCs) andoxidation and corrosion protective overlay coatings in industrial gas turbines. High temperature oxidation behaviour of NiCoCrAlYs has a great influence on the coating performance and lifetime of TBCs. A promising route to decrease the oxidation rate of such coatings is post-coating surface modification which can facilitate formation of a uniform alumina scale with a considerably slower growth rate compared to the as-sprayed coatings. In this work, the effect of surface treatment by means of shot peening and laser surface melting (LSM) on the oxidation resistance of high velocity air-fuel (HVAF) sprayed NiCoCrAlY coatings was studied. Isothermal oxidation was carried out at 1000⁰C for 1000h. Results showed that the rough surface of as-sprayed HVAF sprayed coatings was significantly changed after shot peening and LSM treatment, with a compact and smooth appearance. After the exposure, the oxide scales formed on surface-treated NiCoCrAlY coatings showed different morphology and growth rate compared to those formed on as-sprayed coating surface. The oxidation behaviour of surface treated HVAF-sprayed NiCoCrAlY coatings were revealed and discussed.

3456 251 - 257 of 257
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