The Wear Properties of Ceramic B4C/AI Matrix Composite at Elevated Temperature under Dry Sliding

摘要

Ceramic B4C particulates with an average particle size of 33 μm were reinforced with 6061A1 matrix by novel two step melt stirring at 750~°C. In experimentation, an addition level of 7Wt% B_4Cp and K_2TiF_6 flux is ball milled to achieve 0.15 ratios for 2hours. The B4C particulate composites were characterized and tested for hardness and wear properties evaluation. Scanning Electron Microscopy (SEM) micrographs have fairly dispersed ceramic B4C particulates with in ductile Al matrix attributed to two-step process and K_2TiF_6 flux. Dry sliding wear behavior of prepared ceramic composite were measured by Pin-on-disc wear evaluating apparatus at 200~°C test temperature under atmospheric humidity condition. Results showed that pull-out of B_4Cp, formation of tribo-film and oxidation of Al protects the direct contact of composite pin at interface under room temperature condition whereas at elevated temperature, composite pin suffer severe plastic deformation due to temperature assisted diffusion of Al atoms; thereby decreasing the wear performance of ceramic composite at all loads. /Energy Dispersive X-ray Spectrometry (EDS) were used to identify the type of wear mechanisms and to understand the surface morphology.