Friction and sliding wear studies on functionally graded Al LM25/WC composite

Abstract

Functionally graded LM25/15 wt.% Tungsten carbide composite of dimension Øout 150 mm x Øin 110 mm x 100 mm and thickness 20 mm was studied to understand the influence of process parameters (applied load, sliding velocity, sliding distance) on the dry sliding wear rate and co-efficient of friction. A 5-level 3 parameter central composite design was developed using response surface methodology considering applied load (10-50N), sliding velocity (1-3 m/s) and sliding distance (500-2500 m) as input parameters. Dry sliding experiments were performed on pin-on-disk tribometer at ambient conditions. Significance tests, Analysis of Variance and confirmation experiments were done to check the accuracy of generated regression model. Generated surface plots revealed wear rate to be increasing as applied load and sliding distance increases and decrease as sliding velocity increases. Worn surface analysis performed revealed formation of deep grooves at high load, MML formation at high velocities and heavy delamination and particle pull-out at high sliding distances.