纳米晶NiTi形状记忆合金/Nb纳米线复合材料超弹应力的温度依赖性
Temperature dependence of superelastic stress in nanocrystalline NiTi shape memory alloy/Nb nanowire composite
王涛涛 1武泽园 1李亚鹏 1廖仲尼 1王永善 1刘艳 1唐玲1
作者信息
- 1. 陕西理工大学 材料科学与工程学院,汉中 723003
- 折叠
摘要
NiTi形状记忆合金因其超弹性已经得到广泛应用,然而传统NiTi合金马氏体相变的超弹应力随温度的降低而快速减小(6～7 MPa/K),显著制约了其在宽温域中的应用.本文通过熔炼、锻造及拔丝获得纳米晶NiTi/Nb丝材,然后采用透射电子显微镜、差示扫描量热仪及拉伸试验机分别研究丝材的显微组织、相变行为及超弹性能.结果表明:纳米晶NiTi/Nb丝材中NiTi合金的平均晶粒尺寸为14 nm,丝材在降温和升温过程中分别发生热诱发B2→R相变和R→B2相变.在328～376 K温度范围内,纳米晶NiTi/Nb丝材应力诱发B2→B19'相变超弹应力的平均值为1002 MPa,超弹应力的温度依赖性为4.1 MPa/K.
Abstract
NiTi shape memory alloys have been widely used due to their superelasticity.However,the superelastic stress of martensitic transformation in traditional NiTi alloys rapidly decreases with the decrease of temperature(6-7 MPa/K),significantly limiting their application in a wide temperature range.This study obtained nanocrystalline NiTi/Nb wire through melting,forging and wire drawing,and then studied the microstructure,phase transformation behavior and superelastic properties of the wire using transmission electron microscopy,differential scanning calorimeter and tensile testing machine.The results indicate that the average grain size of NiTi alloy in nanocrystalline NiTi/Nb wire is 14 nm,and the wire undergoes thermally induced B2→R phase transition and R→B2 phase transition during cooling and heating processes,respectively.In the temperature range of 328-376 K,the average value of superelastic stress for stress induced B2→B19′ transformation is 1002 MPa,and the temperature dependence of superelastic stress is 4.1 MPa/K.
关键词
纳米晶/NiTi形状记忆合金/Nb纳米线/超弹应力/温度依赖性Key words
nanocrystalline/NiTi shape memory alloy/Nb nanowires/superelastic stress/temperature dependence引用本文复制引用
基金项目
陕西省自然科学基础研究计划(2022JQ-451)
陕西理工大学人才启动科研基金(209020369)
出版年
2024
NETL
NSTL
维普
万方数据