Elastic anisotropy and low-temperature thermal expansion in the shape memory alloy Cu-Al-Zn

Cu-based shape memory alloys are known for their technologically important pseudo-elastic and shape-memory properties, which are intimately associated with the martensitic transformation. A combination of deformation theory and finite-strain elasticity theory has been employed to arrive at the expressions for higher order elastic constants of Cu-Al-Zn based on Keating's approach. The second- and third-order elastic constants are in good agreement with the measurements. The aggregate elastic properties like bulk modulus, pressure derivatives, mode Gruneisen parameters of the elastic waves, low temperature limit of thermal expansion, and the Anderson-Gruneisen parameter are also presented.