| Title |
Pesearch Paper / Transformations : Shape Memory Characteristics of Ti-Ni-Hf Alloys |
| Authors |
임희중(Hee Joong Im),강상호(Sang Ho Kang),남태현(Tae Hyun Nam) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
Shape memory characteristics of (50-X)Ti-Ni-XHf(X = 0∼20 at.%) alloys have been investigated by means of the thermal cycling tests under constant load. The transformation elongation increased with increasing applied stress. Stress dependence of the martensitic transformation start temperature in Ti-Ni-Hf alloys was higher than that in the Ti-Ni binary alloy. Maximum recoverable elongation decreased with increasing Hf-content and was less than 1% in 15, 20 at.% Hf alloys because preferential arrangements of martensite variants were not developed well. Transformation hysteresis of Ti-Ni-Hf alloys almost did not change with increasing Hf-content and were larger than that of the Ti-Ni binary alloy. Residual elongation of Ti-Ni-Hf alloys was much smaller than that of the Ti-Ni binary alloy and that of the 35Ti-50Ni-15Hf alloy did not occur under applied stress of about 120 ㎫. |