Sinter-Swage Processing of an Al-Si-Mg-Cu Powder Metallurgy Alloy

Abstract

A powder metallurgy (PM) alloy similar to wrought aluminum alloy 6013 was researched. Alloy variants emphasized systems with/without pre-alloyed manganese and admixed elemental tin powder. Systems with pre-alloyed manganese demonstrated an inferior response to die compaction and only achieved a density of 91% of theoretical after sintering. Conversely, the mixture that contained a trace addition of tin and was devoid of manganese densified to >98%. In the T6 state, this particular PM variant exhibited stiffness and yield strength that were comparable to wrought 6013-T6 but maintained a limited tensile ductility. The latter trait, as well as UTS and fatigue performance, were all improved significantly with the inclusion of a hot swaging step after sintering. As hot swaging eliminated the bulk of residual porosity in the sintered preform, this was believed to have underpinned much of the gains realized.