STUDIES ON EROSION WEAR BEHAVIOR OF SIC-WC COMPOSITES

Abstract

Highly densified SiC ceramics were prepared with 0, 10, 30 or 50 wt% WC by hot pressing of SiC, and WC powders, and A1203, Y203, and CaO additives at 1800°C for I h in Ar atmosphere. The ceramic composites were subjected to erosion by a stream of silicon carbide particles (30-70 gm particle size) impinging at angle 90°, 60° and 30° with a mass flow rate of 3 g/min for getting its steady state and erosion rate. Microstructures of the composites consisted mostly of equiaxed SiC grains with WC at grain boundaries. Fracture surfaces showed mixed mode of fracture, with the large extent of transgranular fracture observed in SiC ceramics containing 30 wt % WC. Eroded surfaces of the composites showed fracture, and pull-out of SiC or WC grains and their compaction. Erosion rate of the composites varied from 850.73 mm3/kg to 1223.24mm3/kg for 90° with minimum erosion rate observed for SiC ceramics containing 30 wt % WC. This dissertation includes six chapters in which Chapter 1 gives the brief introduction of the SiC ceramics and its composites. Chapter 2 gives the general description of the theoretical background of erosion and ceramics composites. Chapter 3 discusses about objective of present work. Chapter 4 gives the description about the experimental methodology employed for this dissertation work. Chapter 5 discusses about the results obtained for various experiments conducted. Chapter 6 gives the conclusions of the overall dissertation work. Suggestions for future work and references are given at the end of the