Co含量对Fe-30Ni-xCo-10.5Al-3Nb-0.05B形状记忆合金组织与伪弹性的影响  

Effects of Co Content on Microstructure and Pseudoelasticity of Fe-30Ni-xCo-10.5Al-3Nb-0.05B Shape Memory Alloys

作　　者：陈朝霞 彭文屹[1] CHEN Zhaoxia;PENG Wenyi(School of Materials Science and Engineering,Nanchang University,Nanchang 330013,China;School of Materials Science and Engineering,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]南昌大学材料科学与工程学院,江西南昌330013 [2]华东交通大学材料科学与工程学院,江西南昌330013

出　　处：《热加工工艺》2020年第14期107-110,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51461030);江西省教育厅科学技术研究项目(GJJ160481)。

摘　　要：熔炼了Fe-30Ni-xCo-10.5Al-3Nb-0.05B(x=0、9、18、22,原子分数,%)多晶合金,将合金冷轧后进行固溶和600℃下的时效处理,时效时间为60 h。应用扫描电镜、X射线衍射仪研究了合金组织和物相的变化,并对合金进行了室温下的硬度和伪弹性测试。结果表明:Co含量为0%时,时效后晶内析出γ’和β两相;Co含量为9%~22%时,时效后晶内析出单一的γ’相;随着Co含量的增加,合金晶粒大小逐渐增加,γ’相的粒径也会发生变化。Co含量为0%的合金表现出超弹性,最大可回复应变为5.87%;Co含量为9%~22%的合金表现出伪弹性,其中,Co含量为18%的合金伪弹性最佳,形状回复率达84.00%,可回复应变达5.25%。合金的应力-应变曲线显示,合金伪弹性的来源除了应力诱发的马氏体相变,还存在其它机制。The Fe-30 Ni-xCo-10.5 Al-3 Nb-0.05 B(x=0, 9, 18, 22, at%) polycrystalline alloys were smelted. After cold rolling, the alloy was treated with solid solution and aging at 600℃, and the aging time was 60 h. Scanning electron microscope(SEM) and X ray diffractometer(XRD) were used to study the changes of microstructure and phase of the alloy,and the hardness and pseudoelasticity of the alloy were tested at room temperature. The results show that, when the Co content is 0%, γ’ and β phases are precipitated in the grain interiors, and when the Co content is 9%-22%, a single γ’ phase is precipitated in the grain interiors. As the Co content increases, the grain size of the alloys gradually increases, and the diameter of the γ’ particles also changes. The alloy with Co content of 0% exhibits superelasticity, the maximum recoverable strain is5.87%. The alloys with Co content of 9%-22% exhibit pseudoelasticity. Among them, the pseudoelasticity of the alloy with Co content of 18% is the best, the shape recovery rate is 84.00%, the recovery strain is 5.25%. The stress-strain curves of the alloy show that, there is other pseudoelasticity mechanisms in addition to stress-induced martensitic transformation.

关 键 词：CO含量 Fe-30Ni-xCo-10.5Al-3Nb-0.05B合金 形状记忆合金 伪弹性 析出相 

分 类 号：TG156.92[金属学及工艺—热处理] TG139.6[金属学及工艺—金属学]