Lattice distortion in selective laser melting (SLM)-manufactured unstable ,B-type Ti-15Mo-5Zr-3Al alloy analyzed by high-precision X-ray diffractometry

SCRIPTA MATERIALIA

卷:201

Article

Takase, Aya^1,2  Ishimoto, Takuya²  Suganuma, Ryoya²  Nakano, Takayoshi² 

[1] Rigaku Amer Corp, 9009 New Trails Dr, The Woodlands, TX 77381 USA

[2] Osaka Univ, Div Mat & Mfg Sci, Grad Sch Engn, 2-1 Yamadaoka, Suita, Osaka 5650871, Japan

关键词: Selective laser melting (SLM);    B-type titanium alloys;    Crystal structure;    Residual stresses;    X-ray diffraction (XRD);   

DOI  :  10.1016/j.scriptamat.2021.113953

来源: Elsevier

【 摘 要 】

A peculiar lattice distortion in a selective laser melting (SLM)-manufactured unstable ,B-type Ti-15Mo5Zr-3Al was observed for the first time, through high-precision X-ray diffraction (XRD) analyses. After SLM, Ti-15Mo-5Zr-3Al exhibited a body-centered-tetragonal structure instead of a body-centered-cubic structure; the c -axis was 0.63% shorter than the a -axis. The XRD analyses also revealed tensile residual stresses of 210 +/- 12 MPa at the specimen surface. A numerical simulation indicated rapid cooling during the SLM, which could have caused the residual stresses. A comparison of the partially stress-released SLM specimen and an electron beam melting-manufactured specimen with negligible residual stress suggested that the residual stress caused by the rapid cooling in SLM induced the lattice distortion. This finding is not consistent with the previous understanding that residual stress changes the lattice parameter without lattice distortion. This study provides new insight into lattice distortion generated by a combination of SLM-specific ultrarapid cooling and unstable phases. (c) 2021 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

【 授权许可】

Free