ABSTRACT
In this paper, the effect of die angle and reduction ratio on the pressure and hardness of extruded Al-Mg-Zn alloy was investigated. Medium carbon steel dies with entry angles of 75°, 90°, 105°, 120°, 150° and reduction ratios of 0.21, 0.40, 0.48 and 0.62 were used to extrude the alloy at temperature of 500 0C. The extruded samples were subjected to hardness test using Vickers hardness testing method. The hardness numbers at 200 g load applied using 10 seconds dwell time indicated improvement in the hardness of the extruded alloy. The hardness increased with increase in the die angle and reduction ratio while the extrusion pressure reduced with increase in die angle to a minimum of 90° die angle and then gradually increased with further increase in die angle. A two-factor ANOVA of the extrusion load and pressure with the other variables of the alloys at 0.05 % significance all show significant differences. The results indicate good information for use in the design of dies for applications in extrusion.
