Ni-Ti合金马氏体相变的低频内耗研究

Ni-Ti合金马氏体相变的低频内耗研究 LOW-FREQUENCY INTERNAL FRICTION OF MARTENSITIC TRANSFORMATION OF Ni-Ti ALLOY 刘盛炎 Liu Shengyen Zhou Xiaopin first-author 周小平 用低频扭摆观察了等原子比的NiTi合金在发生正、反马氏体相变时的内耗变化。在室温附近,降温测量到0℃以下,逆转升温测量到60℃以上的过程中,从500℃退火炉冷的试样仅分别观察到单一正马氏体转变内耗峰和反马氏体转变内耗峰。同一试样,悬在扭摆仪中就地经过多次热循环测量,随后在降温测量中逐步发展出来一个位于正马氏体转变峰前的内耗峰,对应于前人在淬火试样中所观察到的予马氏体转变内耗峰,并在频率温度曲线上有对应的明锐频率极小。本工作也观察了降温测量中止的温度对随后逆转升温测量所得的反向转变内耗峰的影响。发现降温测量时,测量中止温度由予马氏体转变温区降至马氏体转变温区时,逆转升温测量所出现的两个对应反相变内耗峰之间有相互消长关系,本文定性地讨论了所观察到的现象。 Low frequecy internal frietion of martensitic phase transformation of NiTi alloy was investigated by means of a torsion pendulum in vacuum. Measuremets were carried out on one single specimen, which was fully annealed at500℃ for 1 hour, followed by furnace cooling. No premartensitic transformation peak was observed from the specimen as-annealed. The development of a premartensitie transformation was followed during the subsequent thermal cycling of the specimen, in situ. With intermediate stop at different temperatures on cooling, a phenomena of development of the reverse martensitic transformation peak at the expense of the reverse premartensitic transformation peak was observed. The results were briefly discussed. 1982-01-01 2021-04-01 1