Warm compaction of aluminium alloy Alumix 123

Abstract

The aims of this study were to understand and improve the mechanical properties of aluminium Al-Cu-Si-Mg P/M alloy Alumix 123 by application of a warm compaction process. They were achieved by investigating the effect of (a) compaction pressure/temperature, (b) admixed lubricants (e.g. Acrawax C and Kenolube P11) on green/sintered density and mechanical properties of compacts. It was found that compaction at 110ºC led to (1) a reduction in the ejection force up to ~ 40 % and (2) an increase in sintered density up to ~ 98 % of theoretical density. After heat treatment at 200ºC for 5 hours (T6), the tensile strength reached ~ 365 MPa and hardness of ~ 126 HV was achieved. Further improvement of mechanical properties of aluminium alloy Alumix 123 can be achieved by reducing the amount of admixed lubricant to 0.5 wt %, and using Acrawax C as the lubricant rather than Kenolube P11. Taguchi analysis was used to identify which parameter (compaction pressure, temperature and lubricant content) affected the densities and mechanical properties of Alumix 123 specimens with single lubricants the most. It was observed that the most effective parameter in warm compaction of Alumix 123 specimens is the lubricant content