Investigating the Tribological Behavior of Aluminum Alloys Produced by a Novel Method: Gas-Induced Semi-Solid (GISS) Casting Technology

Abstract

Aluminum alloys are becoming widely preferred in the automotive industry due to their high specific strength-to-weight ratios. Among these aluminum cast alloys, those with high-silicon content can offer a unique combination of mechanical and better wear properties. In this study, EN AC 46000 (AlSi9Cu3(Fe)), 48000 (AlSi12CuNiMg), and 48100 (AlSi17Cu4Mg) aluminum alloys are produced using high-pressure die casting and gas-induced semi-solid (GISS)-adapted technologies. The effects of GISS adaption on the microstructure and tribological behavior are investigated. The lower casting temperatures and formation of solid particles in the melt by GISS adaption were found to improve the die filling and reduced porosity. This leads to higher hardness and improved wear resistance. Among the six casts investigated, the one with GISS-adapted 48100 (AlSi17Cu4Mg) alloy showed the highest hardness and highest abrasion of the cast iron pin during tribological tests. The enhanced properties are assumed to be the result of its unique microstructure formed due to its high-silicon and copper contents, as well as the decreased microporosity due to the GISS (gas-induced semi-solid) adaption approach.