Microstructural homogeneity and mechanical behavior of a selective laser melted Ti-35Nb alloy produced from an elemental powder mixture
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2021年第2期
论文作者：Jincheng Wang Yujing Liu Chirag Dhirajlal Rabadia Shun-Xing Liang Timothy Barry Sercombe Lai-Chang Zhang
文章页码：221 - 233
摘 要：Although using elemental powder mixtures may provide broad alloy selection at low cost for selective laser melting（SLM）, there is still a concern on the resultant microstructural and chemical homogeneity of the produced parts. Hence, this work investigates the microstructure and mechanical properties of a SLM-produced Ti-35 Nb composite（in wt%） using elemental powder. The microstructural characteristics including ? phase, undissolved Nb particles and chemical homogeneity were detailed investigated.Nanoindentation revealed the presence of relatively soft undissolved Nb particles and weak interface bonding around Nb-rich regions in as-SLMed samples. Solid-solution treatment can not only improve chemical homogeneity but also enhance bonding through grain boundary strengthening, resulting in43 % increase in tensile elongation for the heat-treated Ti-35 Nb compared to the as-SLMed counterpart. The analyses of tensile fractures and shear bands further confirmed the correlation between the different phases and the ductility of Ti-35 Nb. In particular, the weak bonding between undissolved Nb and the matrix in the as-SLMed sample reduces its ductility while the ? grains in solid-solution treated Ti-Nb alloy can induce a relatively stable plastic flow therefore better ductility. This work sheds insight into the understanding of homogenization of microstructure and phases of SLM-produced alloys from an elemental powder mixture.
Jincheng Wang1,2，Yujing Liu2，Chirag Dhirajlal Rabadia1，Shun-Xing Liang1，Timothy Barry Sercombe2，Lai-Chang Zhang1
1. School of Engineering, Edith Cowan University2. School of Engineering, M050, The University of Western Australia
摘 要：Although using elemental powder mixtures may provide broad alloy selection at low cost for selective laser melting（SLM）, there is still a concern on the resultant microstructural and chemical homogeneity of the produced parts. Hence, this work investigates the microstructure and mechanical properties of a SLM-produced Ti-35 Nb composite（in wt%） using elemental powder. The microstructural characteristics including ? phase, undissolved Nb particles and chemical homogeneity were detailed investigated.Nanoindentation revealed the presence of relatively soft undissolved Nb particles and weak interface bonding around Nb-rich regions in as-SLMed samples. Solid-solution treatment can not only improve chemical homogeneity but also enhance bonding through grain boundary strengthening, resulting in43 % increase in tensile elongation for the heat-treated Ti-35 Nb compared to the as-SLMed counterpart. The analyses of tensile fractures and shear bands further confirmed the correlation between the different phases and the ductility of Ti-35 Nb. In particular, the weak bonding between undissolved Nb and the matrix in the as-SLMed sample reduces its ductility while the ? grains in solid-solution treated Ti-Nb alloy can induce a relatively stable plastic flow therefore better ductility. This work sheds insight into the understanding of homogenization of microstructure and phases of SLM-produced alloys from an elemental powder mixture.
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