The effects of wide range of compositional changes on the martensitic transformation characteristics of NiTiHf shape memory alloys

SCRIPTA MATERIALIA

卷:161

Article

Umale, Tejas¹  Salas, Daniel¹  Tomes, Bradley¹  Arroyave, Raymundo¹  Karaman, Ibrahim¹ 

[1] Texas A&M Univ, Dept Mat Sci & Engn, College Stn, TX 77843 USA

关键词: NiTiHf;    Martensitic phase transformation;    High temperature shape memory alloy;    Composition dependence;   

DOI  :  10.1016/j.scriptamat.2018.10.008

来源: Elsevier

【 摘 要 】

The effects of composition on the martensitic transformation characteristics of NiTiHf shape memory alloys are systematically explored. Transformation temperatures (TTs) demonstrate a non-monotonic dependence on Ni and Hf concentrations. For Ni > 50 at%, TTs decrease with small Hf additions, attain a minimum or are completely suppressed, depending on Ni content, followed by a significant increase with Hf content. This initial drop in TTs becomes more pronounced with higher Ni contents and is attributed to the increase in nickel anti-site defects along with bulky substitutional Hf contributing to the increase in local lattice distortions along with the redistribution of Ti and Hf. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free