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研究了在不同拉伸应力约束下经不同热循环次数后TiNi合金的多功能性能(可恢复应变、形状恢复力、上平台应力、阻尼性能SDC)衰减规律。结果表明,在循环初期,随着循环次数的增多,其多功能性能均有所下降;当循环超过一定次数后,多功能性能逐渐趋于稳定。约束应力的大小与达到稳定状态的循环次数有关,但不影响其达到稳定状态的多功能性。在阐明多功能性衰减规律的基础上,得出约束条件造成TiNi合金多功能性能衰减的主要原因是约束条件下马氏体孪晶界面以及位错密度与组态变化的衰减。
The multifunctions (recoverable strain, shape restoring force, upper plateau stress and damping property SDC) of TiNi alloy under different tensile stress constraints were studied. The results show that at the beginning of the cycle, the multifunctional performance decreases with the increase of the number of cycles. When the cycle exceeds a certain number of times, the multifunctional performance tends to be stable. The magnitude of the restraint stress is related to the number of cycles to reach a steady state, but does not affect its versatility to reach a steady state. Based on the elucidation of attenuation law of multifunctionality, it is concluded that the main reason for the multifunctional attenuation of TiNi alloy caused by the restraint conditions is the decay of the martensite twin interface and the variation of dislocation density and configuration under the constraint conditions.