Effect of laser shock on the compacting characteristics and rebound behavior of composite powders (Al2O3/Al) with different alumina contents

Combining the unique advantages of a pulsed laser with its high strain rate dynamic loading features and suitability for microforming, laser shock dynamic compaction experiments were conducted on alumina particle-reinforced aluminum-based composite powders. The effect of laser energy Em and hard particle Al2O3 content (5, 10, 15 wt%) on the relative density（actual density /theoretical density）of the pressed billets was investigated. The research results show that with the increase of laser energy, the relative density of the billet gradually increases and the pores on the surface of the billet gradually decrease. As the Al2O3 content increased, the relative density of the billets showed a decreasing trend, with 97.32%, 95.38%, and 92.67%, and the average microhardness was 61.43 HV, 79.33 HV, and 72.9 HV, respectively. The dynamic response of the press billet, the stress–strain evolution mechanism and the rebound of the press billet under laser loading characteristics were investigated by 3D multiparticle finite element method (MPFEM). The laser shock dynamic compaction of Al2O3/Al composite powder densification process was revealed, and the effects of Em, hard particle Al2O3 content and friction coefficient on the rebound and relative density of the compacted billets were explored. The results show that as the laser energy and Al2O3 particle content increase, the rebound of the pressed billet becomes more pronounced. When the friction coefficient is smaller and the laser energy is higher, the rebound phenomenon of the pressed billet becomes more obvious. The experimental and simulated results were found to be in high agreement, validating the feasibility and accuracy of the 3D MPFEM.