高熵合金中间层对TiNi/TC4电子束焊接头组织及性能影响

Effect of High-Entropy Alloy Interlayer on Microstructure and Properties of TiNi/TC4 Electron Beam Welded Joints

目的解决TiNi/TC4异种金属的焊接问题,扩大此2种金属的结合应用。方法选用3 mm×40 mm×0.5 mm的FeCoCrNiMn高熵合金薄片作为中间层,采用电子束焊接方法焊接TiNi/TC4。对形成的接头进行宏观分析,采用电子显微镜以及X射线衍射仪对其微观组织进行表征;通过拉伸和硬度测试,分析该接头的力学性能。结果接头宏观成形存在裂纹缺陷,观察微观组织发现,在焊接接头中只形成了AlTi_(3)相和Ni_(0.35)Al_(0.30)Ti_(0.35)相,没有形成Ti_(2)Ni相。接头的抗拉强度为81.8 MPa,伸长率为4.38%,平均显微硬度为HV661,断口呈脆性断裂特征。结论将高熵合金作为中间层焊接TiNi/TC4是一种有效的方法,可以成功实现异种金属的焊接,中间层的存在可以有效调控焊缝中的析出相种类。

The work aims to solve the welding problem of TiNi/TC4 dissimilar metals and expand the combined use of these two metals.A 3 mm×40 mm×0.5 mm FeCoCrNiMn high-entropy alloy(HEA)sheet was selected as the interlayer,and TiNi/TC4 dissimilar metals were welded by electron beam welding.The macroscopic analysis of the formed joint was carried out,and the microstructure of the joint was characterized by a scanning electron microscope and an X-ray diffraction.The mechanical properties of the joint were analyzed through tensile and hardness tests.The joint was macroscopically formed with cracking defects and the microstructure showed that only AlTi_(3) and Ni_(0.35)Al_(0.30)Ti_(0.35) were formed in the welded joint,and no Ti_(2)Ni phase was formed.The tensile strength of the joint was 81.8 MPa,the elongation was 4.38%,the average microhardness was HV661,and the fracture was characterized by brittle fracture.Welding TiNi/TC4 with high-entropy alloy as the interlayer is an effective method,which can successfully realize the welding of dissimilar metals.The existence of the interlayer can effectively control the phase formed in the weld.