Record number :
2150141
Title of article :
Effect of annealing and initial temperature on mechanical response of a Ni–Ti–Cr shape-memory alloy
Author/Authors :
Choi، نويسنده , , Jeom Yong and Nemat-Nasser، نويسنده , , Sia، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
8
From page :
100
To page :
107
Abstract :
The effect of the annealing conditions and the initial temperature on the compressive response of a ternary Ni–Ti–Cr shape-memory alloy is investigated at a strain rate of 10−3/s, using an Instron hydraulic testing machine. The annealing temperature and duration considerably influence the forward, from austenite to the stress-induced martensite, and the reverse phase transformation. The transition stress and the yield stress of the resulting stress-induced martensite increase with the increasing annealing temperature. The transition stress reaches its maximum value for an annealing temperature of 573 K, and the yield stress for 673 K. Thereafter, both stresses decrease with further increase in the annealing temperature. The highest transition stress is attained for the smallest precipitates. In addition, the phase transformation upon cooling and heating changes from a single-step to a multiple-step with the decreasing annealing temperature. The transition stress for the stress-induced martensite formation increases with increasing initial temperature at a rate of about 8.5 MPa/K. The optimum annealing condition that produces the highest transition and yield stresses without an accompanying residual strain is 573 K for 60 min.
Keywords :
Initial temperature , Transition stress , Superelastic property , yield stress , Clausius-Clapeyron slope
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Serial Year :
2006
Link To Document :
بازگشت