Thermal fatigue of particle reinforced metal-matrix composite induced by laser heating and mechanical load

摘要

The thermal fatigue of particle reinforced metal-matrix composite induced by repetition-pulsed laser heating and mechanical load was experimentally and numerically studied. It is found that the fatigue damage is initial at the intersection region of laser irradiated brim region and the perpendicular direction of tensile load. The initial damage is induced by void nucleation, growth and subsequent coalescence in the matrix material or interface separation. The fatigue cracks are constituted of void in the matrix, interface separation and particle fracture. The propagation direction of fatigue crack is the perpendicular direction of the tensile load. The fields of temperature, macroscopical stress and microscopical stress and the histories of temperature, macroscopical stress and microscopical stress induced by the repetition pulsed laser and tensile load were simulated by ANSYS-DYNA finite element code. It is found that with the times of laser-irradiated increasing, the maximum temperature within every pulsed laser is increasing. The time of the maximum temperature lagged in the time of the maximum intensity of laser. The maximum stress took place at the intersection region of laser heating brim region and the perpendicular direction of tensile load. Therefore, the damage would be initial at these regions. The results are agreement with the experiment results.