| Title |
Variation of Transformation Temperatures in a Cu - Zn - Al Shape Memory Alloy by heat Treatments |
| Authors |
정인상(In Sang Chung); 박경채(Kyeung Chae Park); 허재룡(Jae Ryong Huh) |
| Abstract |
Variation of martensitic transformation temperatures in the Cu-14.38 Zn-6.75Al (Wt%) Shape memory alloy to heat treated in various conditions was systematically investigated by the use of dilatometry. The stable transformation temperatures(M_s, M_f, A_s, A_f,) of the al1oy are reproducible in the two step quenched alloy(above M_s and subsquently below M_f) rather than in the direct quenched one below M_f. An aging and a thermal cycling has a slight influence upon the transformation temperatures of the alloy due to the stabilization of the corresponding phases. Aging in the parent phase decrease M_s and in the martensite phase increase A_s Transformation temperatures are become constant after 100 cycles during 298 K(＜M_f)↔423 K(＞A_f) cycling. An order of transformation temperatures are changeable from class I (M_f＜M_s＜A_s＜A_f) to class Ⅱ(M_f＜A_s＜M_s＜A_f) or vice versa by a thermal history of the a1loy. |