Mn13钢基材表面真空钎焊Al_(1.2)CoCrFeNi_(2.1)高熵合金的微观组织与性能  

Microstructure and Properties of Vacuum Brazed Al_(1.2)CoCrFeNi_(2.1) High-Entropy Alloy onto the Surface of Mn13 Steel Substrate

作　　者：甘勇 冉旭 邹顺洋 胡永俊[1] 董勇 朱志刚 汪克威 GAN Yong;RAN Xu;ZOU Shunyang;HU Yongjun*;DONG Yong;ZHU Zhigang;WANG Kewei(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学材料与能源学院,广东广州510006

出　　处：《材料研究与应用》2023年第2期295-302,共8页Materials Research and Application

基　　金：广东省国际科技合作项目(2022A0505050052);广东省自然科学基金面上项目(2022A1515012591)。

摘　　要：针对传统钢材Mn13钢等在大规模应用中暴露出的低应力耐磨性差、低温脆性和易生锈等问题,采用在Mn13钢表面焊接具有高强度、良好的延展性和耐蚀性的Al_(1.2)CoCrFeNi_(2.1)近共晶高熵合金来改善其表面性能。采用BNi2钎料通过真空钎焊的方式在Mn13钢表面钎焊Al_(1.2)CoCrFeNi_(2.1)高熵合金,并对高熵合金母材和钎焊接头的微观组织与力学性能进行了探究,同时研究了真空钎焊温度对钎焊层微观组织和力学性能的影响。实验结果表明:母材Al_(1.2)CoCrFeNi_(2.1)高熵合金的显微组织由FCC相和有序B2相组成,钎焊后合金组织中B2相体积分数增加,显微维氏硬度从(436±15.7)HV升至(472±7.1)HV;钎焊接头的微观组织主要为Ni基的固溶体相和硼化物相,焊缝中心主要以CrB为主,扩散区则以B元素与母材元素形成的硼化物为主;钎焊温度过低或者过高会在焊缝形成气孔及硼化物,从而降低钎焊接头的剪切强度,当钎焊温度为1 050℃时,焊接接头的剪切强度达到最大值684.6 MPa。In response to the issues of poor low-stress wear resistance,low-temperature brittleness and easy rusting exposed in large-scale applications of conventional steels such as Mn13 steel,a near-eutectic Al_(1.2)CoCrFeNi_(2.1) high-entropy alloy was welded onto the surface of Mn13 steel to improve its surface properties.The microstructure and mechanical properties of the high-entropy alloy base material and brazed joints were studied by brazing Al_(1.2)CoCrFeNi_(2.1) high-entropy alloy onto the surface of Mn13 steel by vacuum brazing with BNi2 brazing material.The effect of vacuum brazing temperature on the microstructure and mechanical properties of the brazed layer was investigated.The experimental results showed that the microstructure of the base material Al_(1.2)CoCrFeNi_(2.1) high-entropy alloy consisted of FCC phase and ordered B2 phase.The volume fraction of the B2 phase increased in the alloy after brazing,and the microscopic Vickers hardness increased from(436±15.7)HV to(472±7.1)HV.The microstructure of the brazed joint was mainly Ni-based solid solution phase and boride phase.The center of the weld was dominated by CrB,and the diffusion zone was dominated by the borides formed by the B element and the base material element.Brazing temperature that is too low or too high will form pores and borides in the weld,thus reducing the shear strength of the brazed joint.Experiments showed that when the brazing temperature was 1050℃,the shear strength of the welded joint reached a maximum of 684.6 MPa.

关 键 词：BNi2钎料 Mn13钢 高熵合金 真空钎焊 力学性能 

分 类 号：TG139[一般工业技术—材料科学与工程] TG454[金属学及工艺—合金]