【摘要】 在焊接温度分别为860、870、880和890℃,焊接压力为10 MPa,保温时间为60 min的条件下，采用真空扩散焊方法对TC4钛合金和GH4169镍基高温合金异种金属进行焊接。使用扫描电镜（SEM）和能谱仪（EDS）对TC4/GH4169扩散焊接接头的微观组织和断口形貌进行表征，使用万能拉伸试验机对接头进行剪切性能测试。结果表明：TC4/GH4169扩散焊接接头的微观组织根据颜色和形貌，可以分为Ⅰ、Ⅱ、Ⅲ和Ⅳ层；Ⅰ层微观组织形貌呈针状结构，由富Cr和富Ni相的（Ni, Cr, Fe）固溶体组成；Ⅱ层和Ⅲ层是两种母材元素扩散反应区域，呈厚度约为1.5μm的条状结构，分别为Ti（Ni, Fe）和Ti₂Ni相；Ⅳ层位于TC4边缘，主要由主要由浅灰色柳叶状Ti₂Ni相和深灰色连续相α-Ti组成；在890℃/60 min/10.00 MPa焊接工艺时，接头界面微观组织比较致密、无孔洞、无裂纹，接头的剪切强度最高，为155.69 MPa,剪切后接头断口形貌呈现河流状，属于脆性解理断裂。更多还原

【Abstract】 Under the conditions of welding temperatures of 860 ℃, 870 ℃, 880 ℃, and 890 ℃, welding pressure of 10 MPa, and holding time of 60 min, vacuum diffusion welding was used to weld dissimilar metals of TC4 titanium alloy and GH4169 nickel-based superalloy. The microstructure and fracture morphology of the TC4/GH4169 diffusion welded joints were characterized using scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS）, and the shear performance of the joints was tested using a universal tensile testing machine. The results show that the microstructure of the TC4/GH4169 diffusion welded joints can be divided into layers Ⅰ, Ⅱ, Ⅲ, and Ⅳ based on color and morphology. The microstructure of layer Ⅰ shows a needle like microstructure, composed of（Ni, Cr, Fe） solid solutions rich in Cr and Ni phases. Layer Ⅱ and Ⅲ are two diffusion reaction regions of the two base metal elements, presenting a strip-shaped structure with a thickness of about 1.5 μm, consisting of Ti（Ni, Fe） and Ti₂Ni phases, respectively. Layer IV is located at the edge of TC4 and is mainly composed of light gray leaf-shaped Ti₂Ni phase and dark gray continuous phase α-Ti. When welding with the process of 890 ℃/60 min/10.00 MPa, the microstructure of the joint interface is relatively dense, without pores or cracks, the shear strength of the joint is the highest, reaching 155.69 MPa. After shearing, the fracture surface of the joint shows a river-like morphology, belonging to brittle cleavage fracture.更多还原