Grain boundary fracture in CuAlNi shape memory alloys

A series of polycrystalline CuAlNi shape memory alloy (SMA) samples were prepared to observe the deformation and fracture behavior under load. Observations were made of the phase transformation initiated from a notch and the interactions with nearby grain boundaries. A variety of different behaviors were observed. The grain boundaries of each of the samples were analyzed to determine the dependence of fracture behavior on grain boundary characteristics. From the experiments and analysis conducted, it was concluded that grain boundaries with low order coincident site lattices (CSLs) do not fail.