摘要
研究了试验温度、退火温度（ Ｔｈ） 及应力—应变循环对Ｔｉ５０ ．６Ｎｉ 合金弹簧超弹性（ＳＥ） 行为的影响。结果表明，冷拔态Ｔｉ５０ ．６Ｎｉ 合金中温退火后，热循环相变类型为Ａ→Ｒ→Ｍ←——— ，组织呈纤维状。该合金弹簧经６２３ ～７７３Ｋ 退火后，室温下可获得ＳＥ。随试验温度升高，弹簧刚度增加。Ｔｈ≥８２３Ｋ时，ＳＥ特性变坏。应力—应变循环初期，弹簧的切应力、切应变恢复率急剧衰减，随循环次数增加，衰减变慢。预循环训练可增强ＴｉＮｉ 合金弹簧超弹性的稳定性。
Influence of testing temperature, annealing temperature (T\-h) and stress\|strain \{cycle\} on superelasticity (SE) behavior of Ti 50.6Ni alloy coil spring has been studied. After intermediate temperature annealing, the thermal cycling transformation type of the cold worked Ti 50.6Ni alloy was A→R→M←——, and the microstructure was fibrous structure. After annealing at T\-h =623～773K, the SE could be got in the room temperature for this coil spring. With increase of the test temperature, the rigidity of spring was increased. When T\-h ≥823K, the property of SE becomes worse. In initial stage of stress\|strain cycle, the recovery rate of shear stress and strain for the spring was sharp declined. With increas of the cyclic numbers, the declining rate was small. The stability of superelasticity in TiNi SMA coil spring could be enhanced by prior cyclic training.
基金
陕西省教委重点科研基金
