Effect of atmosphere on sintering of Alumix 431D powder

Dilatometry and differential scanning calorimetry analyses were used to study the sintering response of Al based powder mixture produced by ECKA Granules, designated as Alumix 431D. Sintering was carried out in atmospheres of pure nitrogen, nitrogen-hydrogen mixture (95 : 5 by volume) and argon. The atmosphere influences the amount of shrinkage but not the sintering mechanisms. These are similar for all gases; typical liquid phase sintering mechanisms seem to be mainly responsible for the sintering behaviour. As expected, however, nitrogen is the most effective sintering atmosphere in terms of densification. Metallographic examinations are in accord with the results of thermal analyses.