Microstructural characterisation of melt infiltrated boron carbide-aluminium composites

Abstract

The microstructure of boron carbide (B4C) - aluminium (Al) composites produced by reactive infiltration were characterised using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) both attached with an energy dispersive x-ray spectrometer (EDX). The present phases were also identified using an x-ray diffractometer (XRD). TEM investigations demonstrated that coating with an amorphous silica (SiO2) layer could successfully change the surface chemist of the starting B4C powders. SEM examination of the fracture surfaces of the composites revealed that the fracture toughness of B4C-Al composites increases with the amount of Al and the ligament diameter.