Improving the mechanical properties of B4C/Al composites by solid-state interfacial reaction

The effect of solid-state interfacial reaction between B4C and Al was often overlooked in related research. In the present study, B4C/Al composites were successfully produced by hot pressing sintering. Nanoscale interfacial reaction product, aluminum boron carbide (Al3BC), was formed in B4C/Al composites even at a low sintering temperature (570 degrees C). The distribution and properties of the nanoscale Al3BC were characterized by transmission electron microscopy (TEM). The results indicate that the interfacial product Al3BC can disperse into the Al matrix during hot rolling. The Al3BC nanoparticles located in the Al matrix lead to a significant strength improvement, around 65 MPa through the geometrically necessary dislocations (GNDs) strengthening and Orowan strengthening in B4C/Al composites with 30% weight percent of B4C. The contributions of Al3BC formation on strength and strengthening mechanism are discussed in detail. (C) 2020 Elsevier B.V. All rights reserved.