Effects of long-term thermal cycling on martensitic transformation temperatures and thermodynamic parameters of polycrystalline CuAlBeCr shape memory alloy

This study proposes to characterize the effect of long-term thermal cycling on transformation temperatures and thermodynamic parameters of polycrystalline CuAlBeCr shape memory alloy. Structural, morphological and thermal characterizations were performed. The samples were submitted up to 1000 cycles using a dual-bath thermal cycler apparatus. The results show that the thermal cycling has a considerable impact on the transformation behavior of the alloy. Up to 500 cycles, the alloy experienced a one-stage reverse martensitic transformation; after this, it was split into two reactions. From 100 cycles, an increase in temperature ranges ( A_f-A_s ) values of the reverse martensitic transformation was observed, associated with the increase in elastic energy. Our study expands the spectrum of knowledge regarding thermal and structural properties, for CuAlBe system alloys, indicating the thermal cycling conditions to which the alloy must be subjected in order to preserve the characteristics required in a given practical application.