Performance evaluation of some steels as extrusion die on AA6063-type Al-Mg-Si alloy

Abstract

This study deals with the performance evaluation of mild and tool steels, their microstructure and extrusion property associated with changes in induced dies of entry angles 15^o, 45^o and 75^oon AA 6063-type Al-Mg-Si alloy. Based on the service requirement in extrusion operations, microhardness and wear properties are used as criteria. The extrusion operation reveals the formation of clusters, surface modification occurring as a result of various ranges of die angles. The effect of extrusion pressure, sample elongation, hardness and die speed angle are systematically studied using microhardness tester, optical microscope (OPM), scanning electron microscope with energy dispersive spectroscopy (SEM-EDS). The mild steel die enables slips and dislocation movement of the sample to take place with ease than the tool steel dies at 45^oelongation. Formation of Mg₂Si and AlFeSi on mild steel extrusion has significantly influenced its mechanical properties as a result of response to increasing grain boundary which serves as nucleation site for the precipitates. The microhardness and wear resistance of extruded mild steel increased by 90%. Extrusion of the aluminum by the tool steel led to the formation of clusters and stretched along the slip directions.