Unraveling the influence of Al particle size on microstructure and tribological properties of cold sprayed Al/B4C composite coatings. (March 2023) - Zhao, Lijia
Abstract: Metal matrix composites (MMCs) have been widely studied for their excellent mechanical properties. In recent years, cold spray has been successfully used as a solid-state deposition process to prepare a variety of metal matrix composites. However, in pursuit of achieving MMCs coating with excellent wear performance, retention of ceramic particles in the coating has been a great challenge. In this study, the effect of Al particle size on the retention of B4 C particles as well as on the resulting microstructure and tribological properties of cold sprayed Al matrix composites was studied in detail. For this purpose, two kinds of Al/B4 C coatings were prepared by cold spray (CS) using two different sizes of Al powder mixed with irregularly shaped B4 C powder. Results revealed that small-sized Al particles are more conducive to the retention of B4 C particles due to their faster flight speed and more quantity in the feedstock. Further, a high amount of retained B4 C particles significantly improves the bonding strength, hardness, and wear resistance of the coating. With increasing B4 C particles in the coating, the wear mechanism gradually changes from adhesive wear to abrasive wear. Graphical Abstract: ga1