利用新型物理模拟装置进行Mg-Ti旋转摩擦焊过程产热机理及原子扩散行为的研究,该装置包含高速摄像、红外热成像及力学传感器系统。结果表明,摩擦焊过程中,摩擦因数经历两个稳态阶段的变化。第一个稳态阶段为库伦摩擦,以磨蚀为主要形式;第二个稳态阶段为粘着摩擦,以塑性流动为主要形式。另外,随着旋转转速及轴向压力的提高,轴向位移、摩擦温度及摩擦系数的增加率也随之明显提高。Mg-Ti摩擦焊过程存在原子的快速扩散现象,该过程中由摩擦大变形激活的扩散系数大约是热激活扩散系数的105倍。 A new type of physical simulation device was used to study the mechanism of heat generation and atom diffusion in Mg-Ti friction stir welding. The device includes high-speed camera, infrared thermal imaging and mechanical sensor system. The results show that in the friction welding process, the friction coefficient undergoes two steady-state changes. The first steady-state phase is Coulomb friction, with abrasive as the main form; the second steady-state phase is adhesion friction, with plastic flow as the main form. In addition, with the increase of rotational speed and axial pressure, the increase rate of axial displacement, friction temperature and friction coefficient also increases obviously. In the process of Mg-Ti friction welding, there exists the phenomenon of rapid atom diffusion. The diffusion coefficient activated by the large deformation of friction in this process is about 105 times of the thermal activation diffusion coefficient.