ABSTRACT
In the past few years the shape memory alloys have attracted the attention of metallurgists and design engineers because of a number of remarkable properties which open a revolutionary way of designing on the basis of entirely new principles compared with conventional alloys. The striking features of shape memory alloys are all closely related to the martensitic transformation. Concomitant with the homogeneous lattice deformation, caused by the movement of the large blocks of atoms, dominant deviatoric shear displacements can cause an external measurable shape change. The thermoelastic, as well as the burst martensitic transformation, are frequently either partially of fully self-accommodating. The limit on attainable recovery stress at a certain temperature in a prestrained shape memory alloy is the flow stress of the austenitic phase at that temperature. From the design point of view, the shape memory alloys offer attractive advantages in comparison with more conventional alloys.
