Hf含量对Ti_(49-X)Ni_(44)Cu_(6)Y_(1)Hf_(X)形状记忆合金的组织与超弹性的影响  

Effect of Hf Content on the Microstructure and Superelasticity of Ti_(49-X)Ni_(44)Cu_6Y_1Hf_(X)Shape Memory Alloys

作　　者：赵光伟[1,2] 李达 陈健 方东 黄才华 石增敏[2] 叶永盛 ZHAO Guangwei;LI Da;CHEN Jian;FAND Dong;HUANG Caihua;SHI Zengmin;YE Yongsheng(Hubei Engineering Research Center for Graphite Additive Manufacturing Technology and Equipment,China Three Gorges University,Yichang 443002,Hubei,China;College of Mechanical and Power Engineering,China Three Gorges University,Yichang 443002,Hubei,China)

机构地区：[1]三峡大学石墨增材制造技术与装备湖北省工程研究中心,湖北宜昌443002 [2]三峡大学机械与动力学院,湖北宜昌443002

出　　处：《材料导报》2023年第9期154-159,共6页Materials Reports

基　　金：国家自然科学青年基金(51604162);湖北省教育厅科研计划项目(B2020024);石墨增材制造技术与装备湖北省工程研究中心开放基金(HRCGAM202104)。

摘　　要：Ti-Ni-Cu基形状记忆合金具有相变滞后小、可回复应变大、热稳定性好等优良性能。本工作采用非自耗真空电弧熔炼制备了Ti_(49-X)Ni_(44)Cu_(6)Y_(1)Hf_(X)(X=0,2,6,10)形状记忆合金,并研究了Hf含量对其组织、相变行为与超弹性等的影响。结果表明,合金在室温下的主要组织为B2奥氏体与少量化合物相,加载与卸载过程中发生了B2B19′马氏体相变。随Hf含量增加,Ti_(49-X)Ni_(44)Cu_(6)Y_(1)Hf_(X)合金的马氏体相变温度降低,合金的压缩强度和断裂应变均有所降低,应力诱发马氏体的临界应力增加。在压缩应变为3%~11%的应力递增压缩循环过程中,合金出现加工硬化现象,并且可回复应力随着预应力的增加而增加。Hf含量为10%的合金在压缩应变为11%时具有最大的可回复应变7.9%,其中超弹性应变为5.2%。在压缩应变固定为7%的循环压缩过程中,10%Hf的样品循环稳定性较好,可以完全回复。Ti-Ni-Cu based shape memory alloy has excellent properties such as small phase transformation hysteresis,large recoverable strain and good thermal stability.The purpose of this work is to systematically investigate the effect of substituting Hf for Ti on the microstructure,phase transformation and superelasticity of Ti_(49-X)Ni_(44)Cu_6Y_1Hf_X(X=0,2,6,10)alloys.The results show that the main microstructure of the alloy at room temperature is B2 austenite and a small amount of compound phase.And one-step martensitic transformation of B2B19′occurs during the loading and unloading processes.With the increase of Hf content,the martensitic transformation temperature decreases,the compressive strength and fracture strain of the alloy decrease,and the critical stress of stress-induced martensite increases.In the cycle compression tests with an increased compressive strain of 3%—11%,the alloy exhibits work hardening phenomenon,and the recoverable stress increases with the increase of prestress.The sample of 10%Hf has the largest recoverable strain of 7.9%when the compressive strain is 11%,and the superelasti-city strain is 5.2%.In the cycle compression tests with a constant compressive strain of 7%,the sample of 10%Hf has good cyclic stability and can be completely recovered.

关 键 词：形状记忆合金 Ti-Ni-Cu-Y-Hf合金 马氏体相变 超弹性 

分 类 号：TG146.23[一般工业技术—材料科学与工程]