Crystal-plasticity modeling of phase transformation–viscoplasticity coupling in high-temperature shape memory alloys

A coupling between phase transformation and viscoplasticity is observed in HTSMAs during actuation. The dislocations generated retained phases accumulated are responsible for the coupling. It results functional fatigue, which reflected as an alteration properties of alloy, increase irrecoverable deformations. objective present study was to develop a theoretical framework account interactions simulate generation crystal-plasticity based multi-scale approach followed framework. This accounts mechanisms of: transformation, induced plasticity, accumulation martensite, plasticity (in rate-independent manner), rate-dependent manner). accounted by direct effect dislocation densities produced onto resistance martensite. resulted indirect on transformation. On simulating response single crystals polycrystals, anisotropic responses captured at grain scale (from crystals), nearly isotropic macro polycrystals). show consistency property trends (such TT hysteresis) those experimentally macroscale. contributions this presenting (i) texture, (ii) thermal cycling rate (iii) through several randomly oriented polycrystal Ni–Ti–Hf HTSMA. • viscoplasticity-phase modelled crystal plasticity. anisotropy dependence behavior captured. polycrystalline actuation qualitatively predicted. viscoplastic-phase estimated.