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

Abstract

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.

Keywords:

• Aluminium powder metallurgy
• Die compaction
• Sintering
• Al–Cu–Mg alloys
• Tensile properties
• Heat treatment

The authors would like to acknowledge funding assistance provided by the Natural Sciences and Engineering Research Council through the Auto21 Networks of Centers of Excellence via Grant No. C202-CPM.