Strengthening and toughening B4C/Al composites via optimizing the Al2O3 distribution during hot rolling

B4C/Al composites with a high B4C content of 30 wt% were successfully fabricated by hot pressing sintering followed by hot rolling. The influence of hot rolling on the microstructure, mechanical properties, anisotropy and the interfacial conditions of the B4C/Al composites were systematically investigated. The improvement of the interfacial Al2O3 nanoparticles distribution during hot rolling increased both the strength and ductility. After sintering of B4C/Al composites, some Al2O3 nanoparticles aggregated together at the interface between B4C and Al matrix, lowering the interface bonding strength between B4C and Al matrix. The Al2O3 nanoparticles dispersed into the Al grain interior after rolling, leading to a well bonding interface between B4C particles and the Al matrix. In addition, the dispersion of Al2O3 nanoparticles into the Al grain interior contributed to the strength through Orowan strengthening and ductility through the enhancement of dislocation storage ability. The strengthening and toughening mechanisms of the composites are discussed in detail. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

B4C/Al composites with 30 wt% B4C content were successfully fabricated by hot pressing sintering and hot rolling. The influence of hot rolling on the microstructure, mechanical properties, anisotropy, and interfacial conditions of the composites was investigated. The results showed that hot rolling improved the distribution of Al2O3 nanoparticles at the interface, leading to increased strength and ductility of the composites. Additionally, the dispersion of Al2O3 nanoparticles into the Al grain interior contributed to the strengthening and toughening mechanisms through Orowan strengthening and enhancement of dislocation storage ability.