title: Effect of annealing temperature on microstructure and superelastic properties of a Ti-18Zr-4.5Nb-3Sn-2Mo alloy.
abstract: In this study a new superelastic Ti-18Zr-4.5Nb-3Sn-2Mo alloy was prepared by adding 2at% of Mo as a substitute for Nb to the Ti-18Zr-11Nb-3Sn alloy, and heat treatment at different temperatures was conducted. The temperature dependence of superelasticity and annealing texture was investigated. Texture showed a dependence of annealing temperature: the specimen annealed at 923K for 0.3ks exhibited {113}β<47¯1>βtype texture which was similar to the deformation texture, while specimens annealed at 973, 1073K, and 1173K showed {001}β<110>βtype recrystallization texture which was preferable for recovery strain. The largest recovery strain of 6.2%, which is the same level as that of the Ti-18Zr-11Nb-3Sn alloy, was obtained in the specimen annealed at 1173K for 0.3ks due to the well-developed {001}β<110>βtype recrystallization texture. The Ti-18Zr-3Nb-3Sn-2Mo alloy presented a higher tensile strength compared with the Ti-18Zr-11Nb-3Sn alloy when heat treated at 1173K for 0.3ks, which was due to the solid solution strengthening effect of Mo. Annealing at 923K for 0.3ks was effective in obtaining a good combination of a high strength as 865MPa and a large recovery strain as 5.6%. The high recovery strain was due to the high stress at which the maximum recovery stain was obtained which was attributed to the small grain size formed at low annealing temperature.
authors.affiliation: Division of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Jie
authors.initials: J
authors.lastname: Fu
authors.affiliation: Division of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan. Electronic address: heeykim@ims.tsukuba.ac.jp.
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Division of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan; Foundation for Advancement of International Science, Tsukuba, Ibaraki 305-0821, Japan. Electronic address: miyazaki@ims.tsukuba.ac.jp.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Miyazaki
mesh_terms: D000497:Alloys / Q000737:chemistry*; D006358:Hot Temperature; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D014025:Titanium
keywords: Heat treatment; Shape memory alloy; Superelasticity; Texture; Titanium alloy