Powder metallurgy processing of Al-Cu-Mg alloy with low Cu/Mg ratio

The objective of this work was to develop an Al-Cu-Mg alloy with a low Cu/Mg ratio suitable for press and sinter powder metallurgy (PM) processing. A bulk composition of Al-2·3Cu-1·6Mg was explored for this purpose. Data revealed that the alloy exhibited a normal response to uni-axial die compaction with a performance that was aligned with commercial blends. Temperature and tin content were found to influence the sintering response. Once optimised, near-full theoretical density was achieved in the sintered product. The alloy was also responsive to T6 heat treatment. Peak hardness was attained by solutionising at 530°C and then aging at 200°C for 20 h. Tensile data revealed that the alloy exhibited a very well balanced combination of properties in the T1 and T6 tempers. In this sense, relatively high values of yield strength and ultimate tensile strength were accompanied by wrought-like stiffness and levels of tensile ductility that were abnormally high for press and sinter aluminium PM alloys.