Friction heat production and atom diffusion behaviors during Mg-Ti rotating friction welding process
(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. Shaanxi Key Laboratory of Friction Welding Technologies,
Northwestern Polytechnical University, Xi’an 710072, China)
2. Shaanxi Key Laboratory of Friction Welding Technologies,
Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: An innovative physical simulation apparatus, including high speed camera, red thermal imaging system, and mechanical quantity sensor, was used to investigate the friction heat generation and atom diffusion behavior during Mg-Ti friction welding process. The results show that the friction coefficient mainly experiences two steady stages. The first steady stage corresponds to the Coulomb friction with material abrasion. The second steady stage corresponds to the stick friction with fully plastic flow. Moreover, the increasing rates of axial displacement, temperature and friction coefficient are obviously enhanced with the increase of rotation speed and axial pressure. It can also be found that the there exists rapid diffusion phenomenon in the Mg-Ti friction welding system. The large deformation activated diffusion coefficient is about 105 higher than that activated by thermal.
Key words: Mg-Ti; friction welding; rotating friction welding; heat generation; atom diffusion; friction coefficient; Coulomb friction; stick friction