硼元素对CuAlNiMn形状记忆合金微观组织与力学性能的影响  

Effects of B addition on microstructure and mechanical properties of CuAlNiMn shape memory alloy

作　　者：杨院霞 千佳祥 张江 郝刚领[1] 王幸福 王新福 王伟国[1] 李先雨 许巧平[1] YANG Yuanxia;QIAN Jiaxiang;ZHANG Jiang;HAO Gangling;WANG Xingfu;WANG Xinfu;WANG Weiguo;LI Xianyu;XU Qiaoping(College of Physics and Electronic Information,Yan’an University,Yan’an 716000,Shaanxi,China;Key Laboratory of Materials Physics,Institute of Solid State Physics,Chinese Academy of Sciences,Hefei 230031,China)

机构地区：[1]延安大学物理与电子信息学院,陕西延安716000 [2]中国科学院固体物理研究所材料物理重点实验室,合肥230031

出　　处：《材料工程》2024年第10期70-79,共10页Journal of Materials Engineering

基　　金：国家自然科学基金(52061038,51661032,51301150);陕西省“特支计划”区域发展人才专项(2020-44);陕西省青年科技新星资助项目(2013KJXX-11)。

摘　　要：通过在合金中引入微量硼元素,采用真空电弧熔炼炉制备Cu-12Al-4Ni-1Mn-x B(x=0%,0.1%,0.2%,0.3%,质量分数,下同)形状记忆合金,研究硼的添加对合金微观结构、物相转变和力学性能的影响。结果表明:硼的引入可显著细化晶粒,晶粒尺寸从数百微米下降至(11±3.45)μm。硼元素添加后,物相转变温度向高温侧移动,表明相变过程需要更高的热激活能。当硼含量为0.2%时,合金显微硬度得到提升,由未添加硼元素的(301.7±2.6)HV提高至(334.3±3.4)HV,这应与晶粒细化和硬脆相硼化物的析出有关。合金拉伸断裂强度和断后伸长率得到极大提升,当硼含量为0.2%时,断裂强度由(320±2.6) MPa提高至(788±17) MPa,伸长率由(1.44±0.05)%提高至(3.74±0.12)%,固溶退火后,二者进一步提升至(856±10.7) MPa和(5.78±0.16)%。分析表明,细晶强化、硼化物颗粒的沉淀强化以及固溶强化是力学性能提升的主要机制,合金断裂模式由脆性断裂转变为韧性断裂。The Cu-12Al-4Ni-1Mn-xB(x=0%,0.1%,0.2%,0.3%,mass fraction,the same below)shape memory alloys were prepared by vacuum arc melting furnace after introducing trace boron element into the alloy.The influence of boron addition on the microstructure,phase transformation,and mechanical properties of the alloy was investigated.The results show that the addition of boron significantly refines the grain size,with the grain size decreasing from hundreds of microns to(11±3.45)μm.The phase transformation temperature shifts to the high-temperature side after boron is added,indicating that the phase transformation process requires higher thermal activation energy.When the boron content is 0.2%,the microhardness of the alloy is enhanced,from(301.7±2.6)HV without adding boron element to(334.3±3.4)HV,which is attributed to grain refinement and the precipitation of hard and brittle borides.The tensile fracture strength and elongation are greatly improved,with the fracture strength increasing from(320±2.6)MPa to(788±17)MPa,and the elongation increasing from(1.44±0.05)%to(3.74±0.12)%.After solid solution annealing,the fracture strength and the elongation are both further increased to(856±10.7)MPa and(5.78±0.16)%,respectively.Analysis indicates that grain refinement strengthening,precipitation strengthening of borides,and solid solution strengthening are the main mechanisms for the improvement of mechanical properties.The fracture mode of the alloy shifts from brittle fracture to ductile fracture.

关 键 词：CuAlNiMn形状记忆合金 晶粒细化 微观结构 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TB31[金属学及工艺—金属材料]