Enhanced ductility of B₄C/Al composites by controlling thickness of interfacial oxide layer through high temperature oxidation of B₄C particles

Pre-oxidizing of the B₄C particles can regulate the thickness of the interfacial oxide layer between the B₄C particles and the Al alloy matrix in the B₄C/Al composites by adjusting the oxidation temperature and time. This paper studied the effect of oxidation temperature and time on the oxide layer of the B₄C particles, which was oxidized at 500 °C ∼ 650 °C in air quantitatively. Taking the pre-oxidized B₄C particles as raw reinforcements, the B₄C/Al composites with a volume fraction of 15% were prepared by hot pressed sintering method, and the interfacial microstructure and tensile properties of the composites were discussed. The results show that the amorphous oxide layers with different average thickness are produced at the interface of the composites, which prepared by the B₄C particles through different oxidation processes, and the average thickness of the oxide layer has a great influence on the fracture elongation of the B₄C/Al composites. When the average thickness of the oxide layer is 9.6 nm, the composites show the highest value of the fracture elongation (4.2%), 50% and 147% higher than that in the composites with the average thickness of 0 and 37.6 nm. By designing the thickness of the interfacial oxide layer, it is expected to realize the regulation of the tensile properties of the B₄C/Al composites.