Aluminium alloy products, and methods of making such alloy products
OwnerCharles Grant Purnell, Henry Dickinsoninventors
Life of this patent
Estimating the term…
Abstract
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.
Claims36
A metal powder source material for making an aluminium-based sintered product by a powder metallurgy route, comprising a mixture of first, second and third aluminium-containing powders;
- wherein the first powder is of a hypereutectic aluminium-silicon-copper-magnesium alloy, the second powder is of a near-eutectic aluminium-silicon alloy containing from 9 to 13 wt % silicon, and the third powder is of aluminium or a hypoeutectic aluminium alloy containing alloying constituents other than silicon and less than 9 wt % silicon;
- the first and second powders are present in relative proportions to one another lying in the range 35:65 wt % to 65:35 wt %;
- and the third powder is present in a proportion of up to 35 wt % of the total weight of the three said aluminium-containing powders.
A metal powder source material according to any one of the preceding claims, wherein the hypereutectic aluminium-silicon-copper-magnesium alloy of the first powder has a copper content of at least 1 wt %.
A metal powder source material according to any one of the preceding claims, wherein the hypereutectic aluminium-silicon-copper-magnesium alloy of the first powder has a magnesium content of at least 0.2 wt %.
A metal powder source material according to any one of the preceding claims, wherein the third powder is of substantially pure aluminium.
A metal powder source material according to any one of the preceding claims, wherein the third powder is present as 5 to 35% of the total weight of the first three powders.
A metal powder mix suitable for making an aluminium-based sintered product by a powder metallurgy route, comprising a metal powder source material according to any one of the preceding claims, mixed with a sintering aid comprising a fourth, zinc-containing powder, wherein the zinc-containing powder is present as at least 0.5 wt % of the total metal powder mixture.
A method of making an aluminium-based sintered product by a powder metallurgy route, comprising producing a mixture of first, second and third aluminium-containing powders and a sintering aid comprising a fourth, zinc-containing powder, compacting the mixture, and sintering the compacted mixture to produce the product;
- wherein the first powder is of a hypereutectic aluminium-silicon-copper-magnesium alloy, the second powder is of a near-eutectic aluminium-silicon alloy containing from 9 to 13 wt % silicon, the third powder is of aluminium or a hypoeutectic aluminium alloy containing alloying constituents other than silicon and less than 9 wt % silicon, and the fourth powder is a sintering aid comprising zinc or a zinc-based alloy;
- the first and second powders being present in relative proportions to one another lying in the range 35:65 wt % to 65:35 wt %, the third powder being present in a proportion of up to 35 wt % of the total weight of the three said aluminium-containing powders, and the zinc-containing powder being present as at least 0.5 wt % of the total metal powder mixture.
Dependencies are inferred from the claim text.