Optimization of wear parameters of binary Al−25Zn and Al−3Cu alloys using design of experiments

Abstract

Zinc-aluminum alloys have been used as bearing materials in the past. In recent years, binary Al−Zn alloys and Al−Zn−Cu alloys are being used as an alternative to the Zn−Al alloys for bearing applications. In this study, both binary Al−25Zn and Al−3Cu were prepared using stir casting process. Homogenization of the as-cast alloys was performed at 350ºC for 8 h and then, the alloys were furnace-cooled to 50ºC. The homogenization led to the removal of the dendritic structure of the as-cast alloys. After homogenization, wear parameters optimization was carried out using Taguchi technique. For this purpose, L₉ orthogonal array was selected, and the control parameters selected are load, velocity, and sliding distance. The optimum parametric condition was obtained using signal-to-noise (S/N) ratio analysis, and specific wear rate (SWR) is the selected response. The “smaller-the-better” is the goal of the experiment for S/N ratio analysis. After the optimization, confirmation tests were carried out using analysis of variance (ANOVA) from the developed regression equation. Finally, wear mechanism studies were conducted using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) images.

Keywords

specific wear rate / micro-hardness / Taguchi technique / signal-to-noise ratio / analysis of variance / aluminum-zinc alloy / aluminum-copper alloy

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