METHOD FOR PRODUCING A SHAPE MEMORY ALLOY MEMBER HAVING SPECIFIC PHYSICAL AND MECHANICAL PROPERTIES

摘要

ABSTRACT OF THE DISCLOSUREIn the present application, a process has beendisclosed that controls and adjusts the physical andmechanical properties of a shared memory alloy (SMA). Thephysical properties include, but are not limited to, trans-formation temperatures of the various SMA phases, the result-ing hysteresis between such phases, suppression of theMartensite phase in relation to the Rhombohedral phase, andthe relationship between the start and finish temperaturesof the respective phases. Mechanical properties that arecontrolled and adjusted include, but are not limited to, theyield point, ultimate tensile strength, and ductility. Thishas been accomplished by the introduction of a knowninternal stress and the distribution of that stress in theSMA prior to final fabrication of the SMA to a desired shapeand prior to imparting memory through a predetermined heattreatment schedule.