A Statistical Assessment of Casting Quality-Tribological Properties of Eutectic Al-12Si Alloy: Effect of Mg

Abstract

This work was carried out to evaluate the relationship between casting quality and wear properties of Al-12Si eutectic alloy with various Mg contents. Mg additions were selected as 0, 2, 3, and 4 wt.%. A permanent die tensile test mold, step-type mold, and RPT sand mold were used in the characterization of the properties of the castings. The bifilm index was measured for the determination of the casting quality. Mechanical properties such as hardness, UTS, YS, e (%), toughness, impact, and wear rate were investigated. All the results obtained in this study were evaluated via statistical analysis software. It was found that melt quality and bifilm index is the dominant factor that determines the mechanical properties. As Mg content was increased, the size of oxides was getting smaller and their number was increased. The highest wear properties were obtained with the highest Mg addition (4 wt.%) for ball-on-disk tests. According to the pin-on-disk test, in the lubricated conditions, there was no change in wear properties with Mg content. In the dry tests, as the bifilm index was increased, the friction coefficient was decreased due to the higher oxide content of the alloy.