Micromechanical properties and deformation behavior of Al3BC/6061 Al composites via micropillar compression

Al3BC has been proved to be a promising candidate as reinforcement of Al alloy. In this work, Al3BC reinforced 6061 Al composites were in-situ fabricated through a liquid-solid reaction method followed by hot extrusion, and the micromechanical properties as well as deformation behavior of the composites were investigated via micropillar compression. The Al3BC/6061 composites show a significant improvement of compression strength than the matrix alloy, indicating an outstanding strengthening effect of Al3BC. Compared with the large parallel local slip bands on the post-compressed pillars of unreinforced matrix materials, the wrinkled slip bands were observed and homogenously distribute on the post-compressed pillars of the composites, indicating an impeding effect on the propagation of slip bands and a better slip homogenization caused by Al3BC particles. The strengthening mechanisms were also discussed and microstructural characterizations reveal that the high strength of the composites is mainly attributed to its high dislocation density, grains refinement and load transfer effects caused by Al3BC.