The effects of Cu addition and solutionising heat treatment on the microstructure and wear properties of hot-extruded Al–Mg₂Si eutectic alloy

Abstract

This study was undertaken to investigate the effect of different Cu contents (0, 1, 3 and 4.5 wt.%) and solutionising treatment on the microstructure, hardness and wear properties of Al–Mg₂Si eutectic alloy after hot extrusion process. Al-13% Mg₂Si-X%Cu alloys were extruded at 753 K (480 °C) at an extrusion ratio of 6:1 and ram speed of 10 mm/s. The results showed that increasing Cu content enhances the hardness value of the eutectic alloy and reduces the wear rate of hot-extruded specimens as a result of new Cu-containing intermetallic formation. Solutionising heat treatment was also positive in improving both hardness and wear properties. It was found that solid solution strengthening is the main reason for hardness improvement, whilst abrasion characteristic appears to be governing mechanism for wear behaviour of heat treated Al-13wt.% Mg₂Si-4.5 wt.%Cu alloy.

Keywords:

• Al–Mg₂Si eutectic
• extrusion
• microstructure
• wear properties

Acknowledgement

The authors gratefully acknowledge Imam Khomeini International and University of Tehran for financial support this investigation and providing lab facilities.