93W/Ni/Mo1接头的等离子活化扩散焊接研究

Interfacial Microstructure and Mechanical Properties of 93W/Ni/Mo1 Joints by Plasma Activated Diffusion Bonding

摘要:

利用等离子活化技术对93W/Ni/Mo1进行真空扩散焊接，用剪切强度和显微硬度表征焊接接头的力学性能，对焊接界面和接头断口物相及微观结构进行表征分析。结果表明，焊接温度低于800℃时，焊接界面有孔洞，焊接温度高于800℃时，焊接界面良好。焊接接头的剪切强度随着焊接温度的升高先升高后降低，在焊接温度为800℃时接头强度最大为100.2 MPa。焊接温度低于800℃时，焊接界面发生扩散形成固溶体；焊接温度高于800℃时，Ni/Mo1界面生成MoNi高硬度金属间化合物，降低焊接接头结合强度。93W/Ni/Mo1焊接接头的断裂破坏主要发生在Ni/Mo1扩散界面。

Abstract:

Refractory metals 93W and Mo1 were bonded with Ni interlayer by plasma activated sintering. Investigations were mainly focused on the influence of bonding temperatures on the microstructures, elemental distributions across the interfaces and mechanical properties of 93W and Mo1 joints. And fracture mechnism of joints was also analyzed. Reliable bonded joints 93W/Ni/Mo1 were obtained when bonding temperature was above 800℃. Shear strength of 93W/Ni/Mo1 joints firstly increased (650~850℃) and then decreased (800~1000℃) with the rising of bonding temperature, and the maximum strength (100.2 MPa) of joint was obtained at 800℃. Soild solutions were formed at the 93W/Ni and Ni/Mo1 interfaces when bonding temperature was below 800℃, while MoNi brittle phase was emerged at Ni/Mo1 interface which debased the strength of joints. Fracture failure mainly occurs at Ni/Mo diffusion interfaces.