The effect of Al–8B grain refiner and heat treatment conditions on the microstructure, mechanical properties and dry sliding wear behavior of an Al–12Zn–3Mg–2.5Cu aluminum alloy

Abstract

In this study the effect of Al–8B grain refiner on the structural and properties of Al–12Zn–3Mg–2.5Cu aluminum alloy were investigated. The optimum amount for B containing grain refiner was selected as 3.75wt.%. The results showed that B containing grain refiner is more effective in reducing average grain size of the alloy. T6 heat treatment was applied for all specimens before tensile testing. Significant improvements in mechanical properties were obtained with the addition of grain refiner combined with T6 heat treatment. After the heat treatment, the average tensile strength increased from 479MPa to 537MPa for sample refined with 3.75wt.% Al–8B. The fractography of the fractured faces and microstructure evolution was characterized by scanning electron microscopy and optical microscopy.Dry sliding wear performance of the alloy was examined in normal atmospheric conditions. The experimental results showed that the T6 heat treatment considerably improved the resistance of Al–12Zn–3Mg–2.5Cu aluminum alloy to the dry sliding wear.