变形约束时效NiTi形状记忆合金弹簧的双程记忆效应  

Two-way Shape Memory Effect of NiTi Shape Memory Springs Trained by Deformation Constraint Aging

作　　者：王建鑫 田新衍 

机构地区：[1]江西赛维LDK光伏硅科技有限公司,新余338000

出　　处：《材料导报》2015年第10期89-93,共5页Materials Reports

摘　　要：利用变形约束时效的方法制作了双程记忆弹簧,采用DSC和温度-位移记录仪表征了弹簧的相变行为和双程记忆效应。DSC和双程记忆动力学曲线均表明弹簧在升温过程的形状变化由马氏体逆相变M/R→A控制,而冷却过程受A→R→M两阶段相变控制,并且R相变对双程记忆应变量的贡献比马氏体相变的贡献大。与马氏体相变相比,R相变诱发的双程记忆效应具有较窄的动作滞后温度以及很高的记忆稳定性,这与变形约束时效时所获得的一定取向的Ti3Ni4相共格内应力场有关。结果表明:变形约束时效是获得双程记忆弹簧的良好途径,制作方法相对简单,获得的双程记忆应变量大,且稳定性高,尺寸制作具有很强的可设计性以及动作温度的可控性。Two-way shape memory springs were fabricated through stepwise deformation constraint aging. The thermal behaviour and two-way shape memory effect （TW-SME） were characterized by using DSC and temperature- displacement recorder （TDR）. Results from DSC and TDR showed the macroscopic shape change of spring was con- sistent with M/R→A transition upon heating process and A→R→M transitions upon cooling process. It was found that the contribution to TW-SME from R-phase transformation was much greater than that from martensitic transfor- mation. Moreover, TW-SME induced by R-phase transformation demonstrated narrow activated temperature hystere- sis and superior cycling stability, which might be related to the preferred internal stress caused by coherent Tin Ni4 pre- cipitates. The results indicated that the stepwise deformation constraint aging is an effective and promising design method to obtain TW-SME, holding significant advantages regarding easy fabrication, considerable two-way shape memory strain, activated temperature tunability, size accuracy as well as excellent long-term stability.

关 键 词：双程记忆效应 NiTi合金弹簧 约束时效 形状记忆合金 马氏体相变 

分 类 号：O69[理学—化学]