Grain Refinement and Hardness Increase of Titanium via Trace Element Addition

Oh, Jae Min; Lim, Joo Won; Lee, B.-G.; Suh, Chang–Yul; Cho, S.-W.; Lee, S.-W.; Choi, Good-Sun

doi:10.2320/matertrans.m2010175

Cited by 31 publications

(10 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to Multigner et al [ 25 ], it is difficult for residual stress to transfer along the depth direction owing to low strain hardening exponent, even though twinning and dislocation are generated in the Ti64 sample. Moreover, O 2 is involved in the SLM process of Ti64 alloy, leading to grain growth restriction and hence contributing to the hardening effect [ 26 ].…”

Section: Resultsmentioning

confidence: 99%

Effects of Laser Shock Peening on Microstructure and Properties of Ti–6Al–4V Titanium Alloy Fabricated via Selective Laser Melting

et al. 2020

View full text Add to dashboard Cite

Laser shock peening (LSP) is an innovative surface treatment process with the potential to change surface microstructure and improve mechanical properties of additively manufactured (AM) parts. In this paper, the influences of LSP on the microstructure and properties of Ti–6Al–4V (Ti64) titanium alloy fabricated via selective laser melting (SLM), as an attractive AM method, were investigated. The microstructural evolution, residual stress distribution and mechanical properties of SLM-built Ti64 samples were characterized before and after LSP. Results show that the SLM sample was composed of single hcp α’ phase, which deviates from equilibrium microstructure at room temperature: α + β phases. The LSP significantly refines the grains of α’ phase and produces compressive residual stress (CRS) of maximum magnitude up to −180 MPa with a depth of 250 μm. Grain refinement of α’ phase is attributed to the complex interaction of dislocations and the intersection of deformation twinning subjected to LSP treatment. The main mechanism of strength and micro-hardness enhancement via LSP is ascribed to the effects of CRS and α’ phase grain refinement.

show abstract

Section: Resultsmentioning

confidence: 99%

Effects of Laser Shock Peening on Microstructure and Properties of Ti–6Al–4V Titanium Alloy Fabricated via Selective Laser Melting

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Specifically, prior-β grain size reduction is targeted to improve properties such as yield strength, ductility and toughness [15]. Previous research [16][17][18][19][20] has demonstrated that silicon is effective in improving the β-grain density through constitutional supercooling for cast titanium alloys. At the time of writing, there is no commercial grain refining technology available or a clear understanding within the field of the factors that promote effective grain refinement of solidified ALM components.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Grain refinement of wire arc additively manufactured titanium by the addition of silicon

Mereddy

Bermingham

StJohn

et al. 2017

Journal of Alloys and Compounds

134

View full text Add to dashboard Cite

This study demonstrates that silicon additions are effective in refining the microstructure of additive layer manufactured (ALM) titanium components. The addition of up to 0.75wt% silicon to commercially pure titanium manufactured by wire arc ALM results in a significant reduction of the prior-β grain size. It is observed that silicon also reduces the width of the columnar grains and allows for the nucleation of some equiaxed grains through the development of constitutional supercooling and growth restriction. The grain size of the ALM components is compared to a casting process and it is found that the as-deposited microstructure produced during ALM exhibits larger average grain sizes. Using the Interdependence model for predicting grain size, it was determined that the population of nucleant particles that naturally occur in titanium, has comparable potency (i.e. ability to activate at a similar undercooling) regardless of the processing method, however, the ALM process contains fewer, sufficiently potent, nucleant particles than for the casting process due to the effect of subsequent cycles of remelting and heating.

show abstract

“…Precipitation of the titanium silicides in the Ti-Si based alloys is one of the most important processes in the microstructure evolution during heat treatment. Dispersions of the silicide particles can be very effective for strengthening and improving the structural stability of such alloys [7][8][9][10][11]. However, there are many contradictions in the literature about the most thermodynamically favorable structure of precipitates in the a-Ti matrix at low concentrations of Si.…”

Section: Introductionmentioning

confidence: 99%

Ab initio-based prediction and TEM study of silicide precipitation in titanium

Poletaev¹,

Липницкий²,

Kartamyshev³

et al. 2014

Computational Materials Science

View full text Add to dashboard Cite

a b s t r a c tThe literature contains many contradictory data about the most thermodynamically favorable structure of precipitates in a-Ti matrix of the hypoeutectoid Ti-Si alloys. In this work we applied our recently developed thermodynamic model to predict the structure of Ti-Si precipitates in a-Ti matrix of the TiSi alloy with total Si concentration of 0.7 wt.%. We considered all prominent Ti-Si phases such as Ti 3 Si; Ti 5 Si 3 ; Ti 5 Si 4 ; TiSi and two TiSi 2 phases and discovered that formation of the Ti 5 Si 3 phase is more favorable than that of the Ti 3 Si in contradiction with the known phase diagrams. Theoretical result was confirmed by experimental investigation of microstructure and phase composition of the model Ti-0.7Si alloy annealed at 873 K for 10 h. Indeed, the only observed phase has hexagonal Ti 5 Si 3 structure. To ensure the completeness of the results we calculated ab initio elastic constants for all considered Ti-Si phases.

show abstract

Grain Refinement and Hardness Increase of Titanium via Trace Element Addition

Cited by 31 publications

References 12 publications

Effects of Laser Shock Peening on Microstructure and Properties of Ti–6Al–4V Titanium Alloy Fabricated via Selective Laser Melting

Effects of Laser Shock Peening on Microstructure and Properties of Ti–6Al–4V Titanium Alloy Fabricated via Selective Laser Melting

Grain refinement of wire arc additively manufactured titanium by the addition of silicon

Ab initio-based prediction and TEM study of silicide precipitation in titanium

Contact Info

Product

Resources

About