相态对镍钛合金清洁切削性能和表面完整性的影响

Aiming at the high-efficiency and high-speed clean machining of NiTi alloys, through clean cutting technologies such as dry cutting, carbon dioxide and liquid nitrogen cryogenic cutting, the cutting experiments of NiTi alloys in different phases were designed and the cutting performance and surface integrity indicators were compared and analyzed, and the influence rules of material phases and cutting parameters on the cutting processes of NiTi alloys were studied. The results show that the cutting force of the martensitic phase is the largest and that of the austenitic phase is the smallest, the former may reach 1.04~3.84 times of the latter; there are four elements Ni, Ti, O and C in the chips, mainly TiO₂ and NiCO₃ form, the formation of the two compounds changes with the cutting temperature, which in turn causes the chip color to change with the processing parameters; when the feed rate is small, the surface roughness Ra value of the austenitic phase is the largest, and the Ra value of the martensitic phase is the smallest, the former may reach 1.24~1.66 times of the latter; under martensitic phase cutting conditions, when the cutting speed is as 130 m/min, the feed rate is as 0.05 mm/r, and the cutting depth is as 0.2 mm, Ra value reaches the minimum value of 0.73 μm.