Effects of hot rolling on the microstructure, thermal and mechanical properties of CuAlBeNbNi shape memory alloy

In this work, the influence of the hot rolling on the microstructure, thermal and mechanical properties of CuAlBeNbNi shape memory alloy was investigated. A reduction in the amount of austenite phase was observed due to the reduction in thickness for the central region of the samples, and an increase in the amount of this phase for the superficial region. Both the central as well as the superficial region of the analyzed samples showed an abnormal grain growth for a thickness reduction of 50 and 75%, more than twice when compared to the thickness reduction of 21%. The transformation temperatures and thermodynamic potentials were more sensitive to the sample removal region than to the percentage reduction in thickness. In addition, the elastic modulus, estimated by the ultra-micro hardness test, on the superficial region was more than 68% lower than the central region for all thickness reduction. This behavior is associated with a larger amount of the martensite phase on the superficial region, which may be attributed to the superficial oxidation and consequently a compositional modification of the Be content.