Study of wear mechanisms in copper-based SiCp (20% by volume) reinforced composite

Copper-based composites appear to be a promising material for engineering applications due to their excellent thermophysical properties coupled with better high temperature mechanical properties as compared to pure copper and copper alloys. In the present investigation, copper-based SiCp composite (20% SiCp by volume) made by powder metallurgy route is investigated for its wear behaviour in terms of its thermal and mechanical characteristics. Dimensional equation between the interactive variables is stated to relate their influence on wear parameters of the material. Approximate Generalized Experimental Model (AGEM) which offers a better genesis of the wear situation is proposed based on the experimental response data to quantify the influence of interactive parameters on the wear. Copper powder (≤10 μm) and α-SiC particles in the size range of 25-37 μm were used to make green compacts of height to diameter ratio of 0.95-1.0 with compacting pressure of 438 MPa. The compacts sintered at 860 °C in nitrogen atmosphere were subjected to physical, mechanical and microstructural characterization. The wear test with an experimental plan of four loads (15 N, 25 N, 45 N, and 65 N) and four sliding speeds (0.6, 1.2, 1.8, 2.4 m/s) was conducted on Pin-On-Disc machine to record loss in mass due to wear for a total sliding distance of 2500 m. The wear rate (mm3/m) calculated for each load and sliding speed combination was used to state the dimensional equation in terms of wear rate parameter, interface parameter (X) and thermal parameter (Y) defined by dimensional analysis approach to quantify the influence of interactive tribological and materials parameters on the wear system under study. Plotting of wear regime maps has been attempted to delineate the boundaries between competing wear mechanisms which govern the wear modes ranging from mild to severe, oxidative, melt wear and alike. The dominance of a wear regime is discussed in the light of SEM micrographs of worn surfaces as for typical experimental conditions.