Two-way shape memory effect induced by martensite deformation and stabilization of martensite in Ti36Ni49Hf15 high temperature shape memory alloy

• Published in: Materials letters Vol. 57; no. 26-27; pp. 4206 - 4211
• Main Authors: MENG, X. L, CAI, W, ZHENG, Y. F, RAO, Y. B, ZHAO, L. C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.09.2003
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Martensitic transformations; Materials science; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Inorganic compounds; Hafnium alloys; Nickel alloys; Phase transformations; Martensite stabilization; Martensitic transformations; TiNiHf alloy; Ternary alloys; Experimental study; Stress strain; Dislocations; Irreversible processes; High temperature shape memory alloy; Titanium alloys; Shape memory alloy; Two-way shape memory effect; Transition element alloys
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/s0167-577x(03)00291-x

The two-way shape memory effect (TWSME) induced by martensite deformation and the stabilization of martensite of a Ti36Ni49Hf15 high temperature shape memory alloy (SMA) have been investigated. The experimental results indicated that the martensite deformation is an effective method to get TWSME in the Ti36Ni49Hf15 alloy even with a small deformation strain. During martensite deformation the martensite reorientation and the dislocation slip occur simultaneously. Thus an internal oriented stress field is easily created to induce the TWSME. The TWSME of the Ti36Ni49Hf15 alloy shows poor stability during the subsequent thermal cycling. In addition, the martensite stabilization is caused by the martensite deformation. The variation of the elastic and irreversible energies should be responsible for this.