Fabrication of Metal Matrix Composites via High-Speed Particle Implantation

This study deals with the improvement of the wear resistance of aluminum alloys by metal matrix composites (MMCs). The latter were fabricated by implanting high-speed solid particles into the metal surfaces. For that, stainless steel and Fe-based amorphous alloy particles were accelerated to the substrates using high-pressure nitrogen. The effect of multi-particle implantation, particle material properties and kinetic energy at impact, and pre-heating treatment of the substrate on particle implantation was investigated using numerical simulation. In addition, the effect of particle size on the MMCs microstructure, wear resistance, strengthening mechanism, and relative hardness was studied. The results showed that the method simultaneously achieved shot peening and metal matrix composite strengthening, that is, resulted in a double-strengthening effect. Furthermore, high-speed particle implantation effectively improved the wear resistance of the substrate: The wear volume of Fe-based amorphous alloy/Al MMCs was 5% of the untreated aluminum substrate and that of stainless steel/Al MMCs 14-44%. It is believed that laser-assisted particle implantation can be used to efficiently increase the thickness and surface properties of MMCs.