Rheology of Al-Cu-Mg pre-alloyed powder in supersolidus liquid phase sintering process

Sintering process was performed on cylindrical consolidates in dry nitrogen atmosphere at various temperatures ranging from the solidus-to-liquidus temperatures for 30?min at a heating rate of 10°C?min^?1. Beam bending technique has been used to measure the macroscopic apparent viscosity of Al-Cu-Mg pre-alloyed powder (2024 Al alloy). Slumping test has been used to measure the yield strength at temperatures above solidus temperature. Wetting angle and capillary stress were calculated. Results showed that the rheological behaviour of this system follows as Bingham model. The yield stress varies from 0.37?kPa at 580°C to 0.3?kPa at 610°C on air atomised Al-Cu-Mg having 0.1% Sn. The correlation between variations of viscosity as function of temperature has been derived. The activation energy of viscous flow was estimated to 15.164?kJ?mol^?1. Capillary and yield stress decrease by increasing temperature. Maximum densification with minimum distortion is obtained at 600–610°C.