Shape memory effects are based on the shear stress sensitivity of the orientation of
lattice variant and invariant shear which is associated with reversible martensitic
phase transformation. The effect of texture and microstructure of the high
temperature phase was investigated with copper based shape memory alloys. Rapid
solidification can produce either a columnar grain structure with a pronounced 〈100〉
fibre texture, or an equiaxal structure with a grain orientation close to random. It
could be shown that the columnar and textured grain structure produces the
maximum shape memory effect in β-Cu alloys if the ribbon shaped specimen is
exposed to tensile stress parallel to the length of the ribbons. These effects are
explained by the influence of primary texture of the high temperature phase on the
texture which originates in the martensitic low temperature phase if the transformation
occurs under an external load.
