异种钛合金线性摩擦焊组织演变及超扩散机理

Microstructure Evolution and Super-Diffusion Mechanism of Weld Zone of Dissimilar Titanium Alloys After Linear Friction Welding

摘要:

研究了TC11和TC17异种钛合金在不同摩擦压力（22~47 MPa）下的线性摩擦焊组织演变和超扩散机理。通过扫描电子显微镜分析接头的微观结构，并通过电子探针分析了接头界面近域的原子浓度。结果表明，焊缝区域温度超过β相变温度，焊接后接头温度迅速下降，焊缝组织转变为完全再结晶组织。焊缝界面处原子发生了超扩散现象，典型原子的扩散系数约为扩散焊接处原子的100倍。在试验参数范围内，增加摩擦压力会增加典型原子扩散距离。

Abstract:

The microstructure evolution and super-diffusion mechanism of weld zone of TC11 and TC17 dissimilar titanium alloys after linear friction welding under different frictional pressures (22–47 MPa) were investigated. The joint microstructure was analyzed by scanning electron microscope, and the atomic concentration near the joint interface was analyzed by electron probe. Results show that the temperature in the weld zone exceeds the β-phase transition temperature, the temperature of the joint drops rapidly after welding, and the weld microstructure changes to a fully recrystallized microstructure. Super-diffusion of atoms occurs at the joint interface, and the diffusion coefficient of typical atoms is about 100 times higher than that of diffusion welding atoms. Within the experiment parameter range, increasing the frictional pressure can extend the diffusion distance of typical atoms.