Abstract

Shape memory effect is a peculiar property exhibited a series of alloy system called shape memory alloys, which have dual characteristics called thermoelasticity and superelasticity, from viewpoint of memory behavior. These alloys take place in class of advanced novel materials with these properties and response to the external conditions. Two successive crystallographic transformations, thermal and stress induced martensitic transformations govern these phenomena in crystallographic basis. Shape memory effect is performed thermally in a temperature interval on heating and cooling after first cooling and, this behavior can be called thermal memory or thermoelasticity. Superelasticity is performed mechanically by stressing and releasing at a constant temperature in the parent austenite phase region of materials, and this behavior can be called mechanical memory.