【摘要】 钛/钢扩散焊复合构件在航空航天高端制造领域有着广阔的应用前景，然而界面脆性金属间化合物是导致其接头性能劣化的主要原因，文中设计了具有液相分离特征的AlCoCrNiCuAg高熵合金粉末中间层，通过形成部分液相降低了依靠单一塑性变形对连接界面组织性能产生的不良影响，研究了在不同焊接温度作用下AlCoCrNiCuAg高熵合金中间层对TC4钛合金和316L不锈钢真空扩散接头界面组织和力学性能的影响规律.结果表明，接头典型界面结构为α-Ti+β-Ti/β-Ti/β-Ti+Ti（Fe,Ni）+Ti₂Ni/Ti（Fe,Ni）/TiFe₂+Fe₂Cr₅Ti₁₇/Fe₂Cr₅Ti₁₇+λ-（Fe,Cr）₂Ti+α-Fe/γ-Fe.随着焊接温度的升高，与TiFe₂反应层相邻的Ti（Fe,Ni）、α-Fe等反应层厚度逐渐增加，同时接头孔洞等缺陷大幅减少，扩散焊接头抗剪强度在二者协同作用下逐渐升高，在1 010℃/30 min时达到最大181 MPa.高熵合金中间层抑制了接头中TiFe₂等脆性金属间化合物的产生，促进了韧性（Fe,Ni）固溶相的形成，实现了钛/钢的可靠连接.更多还原

【Abstract】 Titanium/steel composite components by diffusion welding have a broad application prospect in advanced aerospace manufacturing.The IMCs are the main reason for the deterioration of the joint performance.AlCoCrNiCuAg high-entropy alloy powder interlayer with liquid phase separation was designed.By forming parts of the liquid phase,the adverse influence of single plastic deformation on the microstructure and mechanical properties of the interface was reduced.The effect of AlCoCrNiCuAg high-entropy alloy powder interlayer on the interfacial microstructure and mechanical properties of the joints between TC4 titanium alloy and 316L stainless steel by diffusion welding at different temperatures was investigated.The results show that the typical interfacial microstructure of the joints is α-Ti+β-Ti/β-Ti/β-Ti+Ti（Fe,Ni）+Ti₂Ni/Ti（Fe,Ni）/TiFe₂+Fe₂Cr₅Ti₁₇/Fe₂Cr₅Ti₁₇+λ-（Fe,Cr）₂Ti+α-Fe/γ-Fe.As the welding temperature increases,the thickness of Ti（Fe,Ni） and α-Fe adjacent to the TiFe₂ reaction layer increases,and the defects at the joint pores are reduced.The shear strength of the joints by diffusion welding exhibits an increasing trend under the synergistic action,and the highest shear strength reaches 181 MPa at 1 010°C for 30 min.The highentropy alloy powder interlayer inhibits the generation of TiFe₂ and other brittle IMCs and promotes the formation of the （Fe,Ni）solid solution phase,achieving a sound bonding between titanium and steel.更多还原