Aluminium alloy products having a pre-sintered density of at least 90 theoretical, and methods of making such alloy products

摘要

Aluminium-silicon powder mixtures comprising a hypereutectic Al—Si powder, a near eutectic Al—Si powder, and a third powder which is aluminium or a hypoeutectic aluminium alloy containing alloying constituents other than silicon and less than 9 wt % silicon, with a sintering aid comprising a fourth, zinc-containing powder, are pressed and sintered to provide powder metallurgy products suitable for automotive component use in particular. The third powder in the composition permits such Al—Si powder mixtures to be compressed to a density approaching that obtained by use of an annealed powder mixture, but without the annealing step.