Change search
Refine search result
1 - 11 of 11
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.
  • 1.
    Babu, Bijish
    et al.
    Mechanics of Sold Materials, Luleå University of Technology, SE-971 87, Luleå, Sweden.
    Charles Murgau, Corinne
    University West, Department of Engineering Science, Avdelningen för svetsteknologi (SV).
    Lindgren, Lars-Erik
    Mechanics of Sold Materials, Luleå University of Technology, SE-971 87, Luleå, Sweden.
    Physically Based Constitutive Model of Ti-6Al-4V for Arbitrary Phase CompositionArticle in journal (Other academic)
    Abstract [en]

    The main challenge in producing aerospace components using Ti-6Al-4V alloy is to employ the optimum process window of deformation rate and temperature in order to achieve desired material properties. Understanding the microstructure property relationship qualitatively is not enough to achieve this goal. Developing advanced material models to be used in manufacturing process simulation is the key to iteratively computeand optimize the process. The focus in this work is on physically based flow stress models coupled with microstructure evolution models. Such a model can be used to simulate processes involving complex and cyclic thermo-mechanical loading

  • 2.
    Charles, Corinne
    University West, Department of Technology, Mathematics and Computer Science, Division for Mechanical Engineering.
    Modelling Microstructure Evolution in Weld Deposited Titanium2007In: NAFEMS Contact Nordic Countries, 2007, NAFEMS Nordic seminar; 4 (Oslo): 2007.03.20-21, 2007Conference paper (Other academic)
  • 3.
    Charles, Corinne
    University West, Department of Engineering Science, Division of Production Engineering.
    Modelling microstructure evolution of weld deposited Ti-6Al-4V2008Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The microstructure and consequently the mechanical properties of titanium alloys are highly dependent on the temperature history endured by the material. The manufacturing process of metal deposition induces repetitive cooling and heating in the material determining a specific microstructure. The presented study is devoted to developing and implementing a microstructure model for Ti-6Al-4V intended to be coupled to a thermo- mechanical model of the metal deposition process.

    Microstructural analysis of the metal deposited samples was first performed to understand the formed microstructure. A set of representative parameters for microstructure modelling were then selected as representative for the known impact of Ti-6Al-4V microstructure on mechanical properties. Evolution equations for these parameters were implemented for thermal finite element analysis of the process. Six representative state variables are modelled: the phase volume fraction of total alpha, beta, Widmanstätten alpha, grain boundary alpha, martensite alpha, and the alpha lath thickness. Heating, cooling and repeated re-heating involved in the process of metal deposition are taken into account in the model. The phase transformations were modelled based on a diffusionnal theory described by a Johnson-Mehl-Avrami formulation, as well as diffusionless transformations for the martensite alpha formation and the beta reformation during reheating. The Arrhenius equation is applied as a simplification to model temperature dependent alpha lath size calculation. Grain growth is not included in the present formulation, but would have to be added for capturing alpha lath coarsening during long term heat treatment.

    The temperature history during robotised tungsten inert gas deposition welding is simulated together with the microstructure. The implementation of the model handles well the complex cyclic thermal loading from the metal deposition process. A particular banded structure observed in the metal deposited microstructure is partially explained using the proposed microstructure model. It is concluded that although qualitatively interesting results have been achieved, further calibration testing over a wider range of temperature histories must be performed to improve the transformation kinetic parameters for reliable quantitative predictions of the microstructure.

  • 4.
    Charles, Corinne
    et al.
    University West, Department of Technology, Mathematics and Computer Science, Division for Mechanical Engineering.
    Järvstråt, Niklas
    University West, Department of Technology, Mathematics and Computer Science, Division for Mechanical Engineering.
    Development of a Microstructure Model for Metal Deposition of Titanium Alloy Ti-6Al-4V2007In: Ti-2007 : science and technology : proceedings of the 11th World Conference on Titanium (JIMIC 5): held at Kyoto International Conference Center, Kyoto, Japan, 3 - 7 June 2007, 2007, p. 1201-1205Conference paper (Refereed)
  • 5.
    Charles, Corinne
    et al.
    University West, Department of Technology, Mathematics and Computer Science, Division for Mechanical Engineering.
    Järvstråt, Niklas
    University West, Department of Technology, Mathematics and Computer Science, Division for Mechanical Engineering.
    Finite Element Modelling of Microstructure on GTAW Metal Deposition of Ti-6Al-4V alloy2006In: Computer Technology in Welding and Manufacturing : 16th International Conference & Mathematical Modelling and Information Technologies in Welding and Related Processes: Kiev, Ukraine, June 6-8, 2006Conference paper (Other academic)
  • 6.
    Charles, Corinne
    et al.
    University West, Department of Engineering Science, Division of Production Engineering.
    Järvstråt, Niklas
    University West, Department of Engineering Science, Division of Production Engineering.
    Modelling Ti-6Al-4V microstructure by evolution laws implemented as finite element subroutines:: Application to TIG metal deposition2008In: 8 th International Conference on Trends in welding research,: Pine Mountain, Georgia, June 2-6, 2008Conference paper (Other academic)
  • 7.
    Charles Murgau, Corinne
    University West, Department of Engineering Science, Avdelningen för svetsteknologi (SV).
    Microstructure model for Ti-6Al-4V used in simulation of additive manufacturing2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is devoted to microstructure modelling of Ti-6Al-4V. The microstructure and the mechanical properties of titanium alloys are highly dependent on the temperature history experienced by the material. The developed microstructure model accounts for thermaldriving forces and is applicable for general temperature histories. It has been applied to study wire feed additive manufacturing processes that induce repetitive heating and cooling cycles.The microstructure model adopts internal state variables to represent the microstructure through microstructure constituents' fractions in finite element simulation. This makes it possible to apply the model efficiently for large computational models of general thermomechanical processes. The model is calibrated and validated versus literature data. It is applied to Gas Tungsten Arc Welding -also known as Tungsten Inert Gas welding-wire feed additive manufacturing process.Four quantities are calculated in the model: the volume fraction of phase, consisting of Widmanstätten, grain boundary, and martensite. The phase transformations during cooling are modelled based on diffusional theory described by a Johnson-Mehl-Avrami-Kolmogorov formulation, except for diffusionless martensite formation where the Koistinen-Marburger equation is used. A parabolic growth rate equation is used for the to transformation upon heating. An added variable, structure size indicator of Widmanstätten, has also been implemented and calibrated. It is written in a simple Arrhenius format.The microstructure model is applied to in finite element simulation of wire feed additive manufacturing. Finally, coupling with a physically based constitutive model enables a comprehensive and predictive model of the properties that evolve during processing.

  • 8.
    Charles Murgau, Corinne
    et al.
    University West, Department of Engineering Science, Division of Welding Technology.
    Lundbäck, Andreas
    Division of Mechanics of Solid Materials, Luleå University of Technology, 971 81 Luleå, Sweden .
    Åkerfeldt, Pia
    Division of Materials Science, Luleå University of Technology, 971 81 Luleå, Sweden .
    Pederson, Robert
    GKN Aerospace Engine Systems, 461 81 Trollhättan, Sweden .
    Temperature and microstructure evolution in Gas Tungsten Arc Welding wire feed additive manufacturing of Ti-6Al-4V2019In: Materials, ISSN 1996-1944, Vol. 12, no 21, article id E3534Article in journal (Refereed)
    Abstract [en]

    The Finite Element Method (FEM) is used to solve temperature field and microstructure evolution during GTAW wire feed additive manufacturing process.The microstructure of titanium alloy Ti-6Al-4V is computed based on the temperature evolution in a point-wise logic. The methodology concerning the microstructural modeling is presented. A model to predict the thickness of the Į lath morphology is also implemented. The results from simulations are presented togethe rwith qualitative and quantitative microstructure analysis.

  • 9.
    Charles Murgau, Corinne
    et al.
    University West, Department of Engineering Science, Division of Production Engineering.
    Pederson, R.
    Luleå University of Technology, Division of Material Science.
    Lindgren, L. E.
    Luleå University of Technology, Division of Material Mechanics.
    A model for Ti-6Al-4V microstructure evolution for arbitrary temperature changes2012In: Modelling and Simulation in Materials Science and Engineering, ISSN 0965-0393, E-ISSN 1361-651X, Vol. 20, no 5, p. 055006-Article in journal (Refereed)
    Abstract [en]

    This paper presents a microstructure model for the titanium alloy Ti-6Al-4V designed to be used in coupled thermo-metallurgical-mechanical simulations of, e.g., welding processes. The microstructure evolution is increasingly taken into consideration in analyses of manufacturing processes since it directly affects the mechanical properties. Thermally driven phase evolutions are accounted for in the model. A state variable approach is adopted to represent the microstructure with the objective to integrate the microstructure changes with a thermomechanical model of manufacturing process simulation such as welding. The model is calibrated using the literature data and also validated against a cyclic temperature history during multi-pass welding.

  • 10.
    Edstorp, Marcus
    et al.
    University West, Department of Engineering Science, Division of Production Engineering.
    Charles, Corinne
    University West, Department of Engineering Science, Division of Production Engineering.
    A Finite Element Methodology for Simulating the Influence of Process Parameters on the Phase Transitions in a GTA weld2009In: Proceedings of the 15th International Conference on the Joining of Materials                , 2009Conference paper (Other academic)
  • 11.
    Lindgren, Lars-Erik
    et al.
    Luleå Technology University.
    Babu, Bijish
    Luleå Technology University.
    Charles, Corinne
    University West, Department of Engineering Science, Division of Production Engineering.
    Wedberg, Dan
    Luleå Technology University.
    Simulation of manufacturing chains and use of coupled microstructure and constitutive models2010In: Finite Plasticity and Visco-plasticity of Conventional and Emerging Materials / [ed] Aktar S Khan, Babak Farrokh,, Fulton, Maryland, USA,: NEAT PRESS , 2010, p. 4 s.-Conference paper (Refereed)
1 - 11 of 11
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