Publication

Abstract : Functionally graded A333/6wt.%B4C/4wt.%ZrO2 hybrid composite manufactured through horizontal-centrifuge casting is subjected to statistical investigation focused on the parametric influences and interactions on wear responses–specific wear rate and coefficient of friction. Taguchi’s L27 orthogonal array design facilitates accurate trend analysis of factors against responses. Mathematical model development using Response Surface Methodology optimizes the wear responses, identifying the most efficient parametric combinations using Analysis of Variance and Signal to Noise ratios. Applied load (10, 30, 50 N), sliding distance (500, 1000, 1500 m) and counter plate hardness (210, 260, 300 HV) are compared to identify the influential hierarchy of factors during pin on plate reciprocating wear tests. The lowest specific wear rate is identified at a combination of 10 N, 500 m, 210 VHN. Whereas, the optimum COF is identified at a combination of 10 N, 500 m, 260 VHN. Quadratic model predicts the wear responses and confirm the closeness (5.2% variance) of predicted values against actual values. The model terms (Load, Distance, Counter plate hardness) of ANOVA with ‘P-value’ less than 0.05 are identified as significant terms. Superior micro-hardness (178.9 ± 1.6 HV) and tensile strength (248.3 ± 2.7 MPa) are observed at the outermost layer (18 mm), which are 35 and 14% higher than the innermost layer (2 mm). Worn surface analysis on the composite specimens identify their corresponding wear mechanisms and counter plate analysis confirm the formation of unstable tribolayer that regulate wear trend.