• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Materials Engineering and Performance >Effect of Cold Rolling on Phase Transformation Temperatures of NiTi Shape Memory Alloy
【24h】

Effect of Cold Rolling on Phase Transformation Temperatures of NiTi Shape Memory Alloy

机译：冷轧对NiTi形状记忆合金相变温度的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The effect of cold rolling and heat treatment on the phase transformation behavior of NiTi shape memory alloy (SMA) heat treated at 660 A degrees C has been investigated. Four sets of samples were cold rolled after heat treatment. The austenite-to-martensite and martensite-to-austenite transformation temperatures for samples without any cold rolling are determined through differential scanning calorimetry (DSC). The austenitic start temperature gets shifted to the higher temperature side with increase in the percentage of the cold rolling up to 12.5%. Austenitic finish temperature could not be detected in cold-rolled samples. Martensitic start temperature increases slightly with increased cold rolling while martensitc finish temperature slightly decreases. Beyond 12.5% cold work, the shape memory effect (SME) is completely lost. The evolution of austenitic phase in SMA subjected to cold rolling was studied through powder x-ray diffraction (XRD) at different temperatures in the range 25 to 160 A degrees C at intervals of 10 A degrees C, during heating and cooling. The XRD results agree with those of DSC. Two sets of cold-rolled samples were again heat treated to 300 and 500 A degrees C and the transformation behavior was studied using DSC. Heat treatment at 300 A degrees C brings back the SME, but with the presence of an intermediate R-Phase due to the additional dislocations present. Even with a heat treatment at 500 A degrees C, the effect of cold work is not completely removed and a single-step transformation is not observed. Another set of samples subjected to cold work were heat treated at 660 A degrees C and the transformation is studied. The effect of cold work even up to 25% is completely removed with this heat treatment as indicated by DSC. The complete regaining of the SME is further confirmed by electrical resistivity measurements also.
机译：研究了冷轧和热处理对在660 A的温度下热处理的NiTi形状记忆合金（SMA）的相变行为的影响。热处理后将四组样品冷轧。通过差示扫描量热法（DSC）确定样品的奥氏体到马氏体和马氏体到奥氏体的转变温度。随着冷轧百分比的增加，奥氏体起始温度移至较高温度侧，达到12.5％。冷轧样品中未检测到奥氏体终点温度。马氏体开始温度随冷轧的增加而略有增加，而马氏体结束温度则略有下降。超过12.5％的冷加工，形状记忆效应（SME）完全消失。在加热和冷却期间，通过粉末X射线衍射（XRD），在25至160 A摄氏度范围内，以10 A摄氏度为间隔，通过粉末X射线衍射（XRD）研究了奥氏体相在冷轧过程中的演变。 XRD结果与DSC一致。将两组冷轧样品再次热处理至300和500 A摄氏度，并使用DSC研究转变行为。在300 A摄氏度下进行热处理可以使SME恢复，但由于存在其他位错，因此存在中间R相。即使在500 A摄氏度下进行热处理，也无法完全消除冷作的影响，也无法观察到单步转变。另一组经过冷加工的样品在660 A的温度下进行了热处理，并对转变进行了研究。如DSC所示，通过这种热处理可以完全消除甚至高达25％的冷作效果。 SME的完全恢复也可以通过电阻率测量得到进一步确认。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号