Preliminary Results of W Fiber Reinforced W (W_f/W) Composites Fabricated with Powder Metallurgy

The first attempt at developing chopped W fiber-reinforced W (W_f/W) composites without an engineered interface or inter-phase employing hot isostatic pressing (HIP) has been made in order to study the feasibility of the powder metallurgy (PM) fabrication methodology. Micro-structures and flexural properties of sintered compacts have been examined by an optical microscope (OM), a scanning electron microscope (SEM) equipped with an electron back scattering diffraction (EBSD) instrument and three-point bending (3PB) tests. There are some chrysan-themum-like grains around each fiber in W matrices. Mechanical properties, namely strength and pseudo-plasticity, of the sintered compacts are far from satisfactory. Abnormal grain growth does not seem to have a preferential growing direction according to EBSD results. Possible causes for the abnormal grain growth and further mechanical property optimizations are hereby presented.