G.B.Schaffer and B.J.Hall, “The Influence of the Atmosphere on the Sintering of Aluminium” Metallurgical and Materials Transactions, in press

Alloys of Al, Al-0.15Mg and Al-12Sn made using air atomised powder and pressed to green densities of 75-98 % were sintered under argon or nitrogen. Sintering in argon is only effective at high green densities when magnesium is present. In contrast, highly porous aluminium can be sintered in nitrogen without the need for magnesium. The oxygen concentration in the gas is reduced by the aluminium through a self gettering process. The outer layers of the porous powder compact serve as a getter for the inner layers such that the oxygen partial pressure is reduced deep within the pore network. Aluminium nitride then forms, either by direct reaction with the metal or by reduction of the oxide layer, and sintering follows.

Return to: Key Publications.