Effect of high-temperature treatment on the structure and properties of TiNi-base alloys

Microstructure and phase transformation of nickel-titanium shape memory alloy fabricated by directed energy deposition with in-situ heat treatment

“…This reduction of Ti2Ni precipitation is caused by the reverse peritectic reaction and/or the instant high solution treatment. A similar result was also reported by Gusev et al [45], where the volume fraction of Ti2Ni precipitation presented a reduction trend when the NiTi alloys underwent a high temperature treatment in the range of 700°C-1100°C. Due to the reduction of the Ti2Ni fraction in the structure, the phase transformation resistance will be decreased.…”

“…Meanwhile, the maximum temperature during reheating process reaches about ~1207°C, above the peritectic reaction temperature of Ti2Ni precipitation. Based on previous research [45,46], the high temperature treatment of NiTi alloy up to 1100°C can effectively decrease the grain size and volume fraction of the Ti2Ni phase. Moreover, high solution treatment has been proven to improve microstructure homogenization [47] and eliminate dislocations [48].…”

Production of niobium vacuum-arc coating on a TiNi-based alloy

“…3 b. This low-temperature effect also cannot result in a change in the volume fraction of the Ti 2 Ni particles and a respective change of titanium-tonickel percentage ratio in the matrix of the alloy, since these particles are thermally stable up to high temperatures [28].…”