Optimum temperature for recovery and recrystallization of 52Ni48Ti shape memory alloy

Results of recent studies on the effect of heat treatment after cold rolling on mechanical properties and transformation temperatures of the cast 52Ni48Ti alloys are described. It is seen that stress-induced martensite is formed when both the as-rolled and the low-temperature (<= 400 degrees Q heat-treated samples are strained. Martensite reorientation due to the stress action occurs in samples heat treated at 500 degrees C and higher. Optimum recovery occurs below 600 degrees C resulting in hardness reduction. Recrystallization starts at 600 degrees C resulting in parent phase yield stress enhancement. Yield stress starts to decrease when grain growth and order-disorder transformation both occur above 700 degrees C. (C) 2006 Elsevier Ltd. All rights reserved.