THERMAL AND TRIBOLOGICAL CHARACTERISATION OF ASBESTOS-FREE PARTICULATE CERAMIC MATRIX COMPOSITES

Abstract

Production of friction particulate ceramic matrix composites (PCMCs) by powder metallurgy method was carried out using iron 105 μm millscale, 50 μm silica sand, 80 μm magnesia and 53 μm bentonite clay as input materials. Different formulation of the blend of these materials were prepared and the composites were produced. Microstructural, frictional, thermal and wear characterisation were determined using standardised methods. The ceramic composites exhibited very good properties in terms of thermal stability (heat resistance), coefficient of friction (COF) and resistance to wear. The specific values of these properties exhibited by sample D having 12 wt. % iron millscale addition in terms of high resistance to thermal decomposition in the temperature region (0 – 1600 0 C) indicating thermal stability, appreciable high COF (0.59) and very low wear rate of 1.9093 x 10-6 g/m are desirable. The uniform dispersion of the particles as observed in the microstructure and strong bonding/adhesion contributed to the enhancement of the properties. These results are indication that the composite is very suitable for application in areas where high resistance to thermal stress and abrasive wear are required such as the brake assembly of automobiles, specifically the brake pads.

Keywords

• particulate ceramic matrix composites
• powder metallurgy
• coefficient of friction
• thermal behaviour and wear characteristics.