Experimental study on the formation of shear bands and effect of microstructure in Al-2124/SiCp composites under dynamic compression

Al-2124 alloy reinforced with 17% vol. SiC particles with three sizes 3, 13, 37µm (MMCs) were tested under impact compression using a Split Hopkinson Pressure Bar(SHPB) system. Microexaminations of tested samples revealed microscopic characteristics of the formation of shear bands occurring in the MMCs. As a comparison, the matrix material, Al-2124 alloy was also tested. Shear bands formed more readily in Al-2124/SiCp reinforced with 3µm particles than in Al-2124 alloy and the alloy reinforced with 13 or 37µm SiC particles. The relations between microstructural distributions, spacing of SiC particles and formation of shear bands have been analysed