Experimental analysis of anodic coating process parameters of Al 5754 alloy by response surface method

Abstract

Aluminum 5754 alloy appears as a candidate material for many engineering applications in terms of its lightness and strength values. The surface properties of this alloy need to be improved for applications where there is surface damage such as friction and wear. In this study, Central composite design was applied to investigate the influences of anodic coating process parameters (voltage, coating time and grit size) on the response (i.e. surface roughness and coating thickness). The competence of the mathematical models recognized, and the importance of the regression coefficients were studied by ANOVA. The initial surfaces of the samples were sanded with 400, 800 and 1200 grit size and surfaces with 3 different roughnesses were obtained. Al 5754 specimens were anodic coated at 8 V, 12 V and 16 V voltages and combinations of time parameters of 10, 20 and 30 min The ANOVA results show that the designed models by RSM for average coating thickness and surface roughness are statistically important at the confidence level of 95%, and 80%, respectively. Maximum anodic coated layer of 29 μm was obtained at surface prepared with 1200 grit size, at 16 V of voltage and used for 30 min of anodizing time. The lowest roughness value of 0.676 μm was obtained at the surface was prepared with 1200 grit size, 8 V of voltage and anodizing time of 10 min.