SELECTIVE LASER MELTING OF the Ti–(40–50) wt.% Nb ALLOY

Sharkeev, Yu. P.; Дмитриев, А. И.; Knyazeva, A. G.; Eroshenko, A. Yu.; Сапрыкин, А.А.; Химич, М. А.; Ibragimov, Egor A.; Глухов, И. А.; Mairambekova, A. M.; Nikonov, A. Yu.

doi:10.1615/hightempmatproc.2017024814

Cited by 7 publications

(6 citation statements)

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“…TEM results confirm that the nanoscale α"-phase precipitations are localized inside microscale β-phase grains and throughout their boundaries (Figures 8b and 9b) [67,68]. The presence of the nonequilibrium nanoscale α"-phase is caused by rapid cooling conditions of samples during the LPBF process and elemental composition's non-uniformity [67,68]. In addition, this could be due to the presence of a small amount of nanoscale α"-phase in the initial mechanically alloyed powder applied for LPBF.…”

Section: Resultssupporting

confidence: 69%

“…nanosized precipitations inside the grain and throughout the grains' boundaries are visible in TEM (Figure 8b). As previously shown in various reports [61,67,68], these are the main β-phase grains with the size of tens of µm and precipitations of the non-equilibrium α″-phase with the size of dozens of nm. The length of the α″-phase's grains does not exceed 1000 nm and that transverse size is in the range of 90-200 nm.…”

Section: Resultssupporting

confidence: 63%

“…The Nb concentration within the nano-scaled α"-grains does not exceed 25 wt.%, which is the same as for the porous LPBF sample. TEM results confirm that the nanoscale α"-phase precipitations are localized inside microscale β-phase grains and throughout their boundaries (Figures 8b and 9b) [67,68]. The presence of the nonequilibrium nanoscale α"-phase is caused by rapid cooling conditions of samples during the LPBF process and elemental composition's non-uniformity [67,68].…”

Section: Resultssupporting

confidence: 61%

“…Before carrying out the LPBF of Ti-Nb samples, the numerical simulation of the mixture crystallization that consists of pure Ti and Nb nanoparticles during their fusion was completed, following the framework of the molecular dynamics method (MD) [ 66 ]. The description of the applied numerical model, its validation, and verification was reported elsewhere [ 67 ]. According to the results of the simulation, the value of the temperature gradient imitating the process of the laser beam influence during the LPBF affects the fraction of atoms that form on the bcc structure of the Ti-Nb alloy.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, this could be due to the presence of a small amount of nanoscale α″-phase in the initial mechanically alloyed powder applied for LPBF. Such structure features and phase composition provide a reduced Young’s modulus of the alloy (in comparison with the modulus of pure components), which is in the range of 60–85 GPa for porous and dense samples, and increased microhardness of 7500 MPa [ 67 , 69 ].…”

Section: Resultsmentioning

confidence: 99%

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Advances in Laser Additive Manufacturing of Ti-Nb Alloys: From Nanostructured Powders to Bulk Objects

et al. 2021

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The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm. The manufactured porous samples have pronounced open porosity and advanced roughness, contrary to dense samples with a relatively smooth surface profile. The structure of both types of samples after LPBF is formed by uniaxial grains having micro- and nanosized features. The inner structure of the porous samples is comprised of an open interconnected system of pores. The volume fraction of isolated porosity is 2 vol. % and the total porosity is 20 vol. %. Cell viability was assessed in vitro for 3 and 7 days using the MG63 cell line. With longer culture periods, cells showed an increased cell density over the entire surface of a porous Ti-Nb sample. Both types of samples are not cytotoxic and could be used for further in vivo studies.

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