Tribological and wear performance of centrifuge cast functional graded copper based composite at dry sliding conditions

Abstract

Non lubricated slide performance of functional grade copper matrix composite, fabricated using horizontal centrifuge cast technique was investigated using pin-on-disc tribo-tester. Rate of wear and friction coefficient of the inner wall thickness of hollow cylindrical cast specimen was analyzed using Taguchi based L27 orthogonal array, where the percentage of graphite particles were observed higher. Variable process parameters those influenced the rate of wear directly or indirectly were: applied load (15, 25 and 35 N), slide velocity (1.5, 2.5 and 3.5 m/s) and slide distance (750, 1500 and 2250 m). Rate of wear and friction coefficient showed a proportional dependency with applied load and slide distance, whereas showing a decline during intermediate slide velocity. Signal-to-Noise ratio predicted the minimal tribo-condition, on ‘smaller-the-better’ basis. Analysis of Variance technique quantified the influence of affecting parameters, along with their interactions. Regression analysis was utilized for the validation of the experimental data. Micrographs and scanning electron microscopy exhibited the wear mechanisms and mechanically mixed layer formation during worn surfaces analysis.