Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Microstructure model for Ti-6Al-4V used in simulation of additive manufacturing
University West, Department of Engineering Science, Avdelningen för svetsteknologi (SV). (PTW)ORCID iD: 0000-0002-3687-7782
2016 (English)Doctoral 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.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2016. , 159 p.
Series
Doctoral thesis / Luleå University of Technology, ISSN 1402-1544
Keyword [en]
Titanium alloy, Ti-6Al-4V, Welding, Metal deposition, Additive manufacturing, Wire feed, Finite Element Method, Microstructure model, Johnson-Mehl-Avrami- Kolmogorov, Thermally driven
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
URN: urn:nbn:se:hv:diva-9346ISBN: 978-91-7583-579-2 (print)ISBN: 978-91-7583-580-8 (print)OAI: oai:DiVA.org:hv-9346DiVA: diva2:927907
Public defence
2016-05-24, E246, Luleå tekniska universitet, Luleå, 09:30 (English)
Opponent
Supervisors
Available from: 2016-05-13 Created: 2016-05-13 Last updated: 2016-05-13Bibliographically approved
List of papers
1. Development of a Microstructure Model for Metal Deposition of Titanium Alloy Ti-6Al-4V
Open this publication in new window or tab >>Development of a Microstructure Model for Metal Deposition of Titanium Alloy Ti-6Al-4V
2007 (English)In: 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, 1201-1205 p.Conference paper (Refereed)
National Category
Metallurgy and Metallic Materials Materials Engineering
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-193 (URN)978-4-88903-406-6 (ISBN)
Available from: 2009-04-22 Created: 2009-04-22 Last updated: 2016-05-13Bibliographically approved
2. Modelling Ti-6Al-4V microstructure by evolution laws implemented as finite element subroutines:: Application to TIG metal deposition
Open this publication in new window or tab >>Modelling Ti-6Al-4V microstructure by evolution laws implemented as finite element subroutines:: Application to TIG metal deposition
2008 (English)In: 8 th International Conference on Trends in welding research,: Pine Mountain, Georgia, June 2-6, 2008Conference paper (Other academic)
National Category
Metallurgy and Metallic Materials
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-2064 (URN)
Available from: 2009-12-17 Created: 2009-12-17 Last updated: 2016-05-13Bibliographically approved
3. A model for Ti-6Al-4V microstructure evolution for arbitrary temperature changes
Open this publication in new window or tab >>A model for Ti-6Al-4V microstructure evolution for arbitrary temperature changes
2012 (English)In: Modelling and Simulation in Materials Science and Engineering, ISSN 0965-0393, E-ISSN 1361-651X, Vol. 20, no 5, 055006- p.Article in journal (Refereed) Published
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.

Keyword
alpha+beta titanium-alloys, phase-transformation, beta-phase, kinetics, steels, martensite, austenite, decomposition, simulations, growth
National Category
Robotics
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-4526 (URN)10.1088/0965-0393/20/5/055006 (DOI)000305805200006 ()2-s2.0-84862730510 (ScopusID)
Available from: 2012-08-02 Created: 2012-08-02 Last updated: 2016-05-13Bibliographically approved
4. Temperature and microstructure evolution in Gas Tungsten Arc Welding wire feed additive manufacturing of Ti-6Al-4V
Open this publication in new window or tab >>Temperature and microstructure evolution in Gas Tungsten Arc Welding wire feed additive manufacturing of Ti-6Al-4V
(English)Article in journal (Other academic) Submitted
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.

Keyword
Additive manufacturing, Titanium, Ti-6Al-4V, modeling, metal deposition, Finite Element
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-9344 (URN)
Note

Ingår i avhandling

Available from: 2016-05-13 Created: 2016-05-13 Last updated: 2016-05-13Bibliographically approved
5. Physically Based Constitutive Model of Ti-6Al-4V for Arbitrary Phase Composition
Open this publication in new window or tab >>Physically Based Constitutive Model of Ti-6Al-4V for Arbitrary Phase Composition
(English)Article in journal (Other academic) Submitted
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

Keyword
Finite Element Method, Dislocation density, Vacancy concentration, Ti-6Al-4V, Alpha, Beta
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-9345 (URN)
Note

Ingår i avhandling

Available from: 2016-05-13 Created: 2016-05-13 Last updated: 2016-05-13Bibliographically approved

Open Access in DiVA

No full text

Other links

Till avhandlingen

Search in DiVA

By author/editor
Charles Murgau, Corinne
By organisation
Avdelningen för svetsteknologi (SV)
Manufacturing, Surface and Joining Technology

Search outside of DiVA

GoogleGoogle Scholar

Total: 377 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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