Cold Back-Pressure Extrusion of Aluminium Powder

Abstract

An investigation was carried out on a new technique of powder metallurgy which could produce an aluminium alloy competitive with SAP (Sintered Aluminium Products) produced at high temperature. Apparent density and hardness of the extruded material increased with increasing back pressure to reach constant maximum values. The effect of temperature on ductility is very small especially in the range from 300°C to 500°C. Tensile strength and hardness at elevated temperatures up to 500°C are significantly higher in the present extruded material than in conventional aluminium alloys. These mechanical properties are very similar to those of SAP, which leads to the conclusion that a dispersion strengthened aluminium alloy can be obtained even at room temperature. The estimated pressure during extrusion processes showed a good approximation to the condition required for pressure bonding of pure aluminium.