Effect of Multi-Axial Room-Temperature Forging on Scratch Hardness and Wear Properties of Hypoeutectic Al-7.3Si and Eutectic Al-12.1Si Alloys

Abstract

In this work, effect of multi-axial room temperature forging process on scratch and wear characteristics of Al-7.3 and Al-12.1Si alloys with varying cumulative strains was investigated. Al-7.3 and Al-12.1Si alloy ingots were remelted in a furnace and then poured into a preheated die to produce a cast sample of the desired shape and dimension for the MAF process. These samples were subjected to solution heat treatment before forging Scratch test was conducted to measure the scratch resistance of unprocessed and MAF-processed samples. Dry sliding wear tests were performed on a tribometer (pin-on-disk) at ambient temperatures. MAF-processed materials exhibited better scratch and wear resistance compared to as-cast materials. After MAF, wear mechanisms in both alloys shifted from adhesive and delamination wear to a combination of abrasive and a lesser amount of adhesive wear. Moreover, the degree of delamination significantly decreased after MAF-process. Improved scratch and wear resistance is mainly due to increased microhardness via refinement and improved uniformity in the redistribution of eutectic silicon as well as the strain hardening of the aluminum phase. © ASM International 2023.