Influence of gamma(2) precipitates in the training of alloys with memory effect

The "training" means the thermomechanical treatment to produce the Two Way Memory Effect (TWME). The TWME is the spontaneous change of shape, carried out by heating and/or a cooling between two shapes: the host shape (austeni tic) and the cool one (martensitic), without any applied stress. The traini ng produces different crystal defects in the austenitic phase, like disloca tion arrangements. Those arrangements produces residual stresses and marten sitic transformation temperature shifts. The training can be modified by th e precipitate presence. We have treated the alloy to produce different dist ributions and sizes of precipitates of gamma 2 phase into the beta phase, b y heating at 400 degrees C. In this work, we have studied the influence of gamma 2 precipitates in the process of training. We have shown that efficie ncy of training is increased for some aging times, i.e., a precipitate size done.