Cooling rate calculation of pure aluminum solidified during a novel gas-assisted continuous casting and extrusion process

Abstract

Gas-assisted continuous casting and extrusion (GAC) process is a novel technique for the continuous preparation of non-equilibrium solidified materials. To evaluate the solidification rate of the melt during GAC, the cooling rate of pure aluminum melt solidified in the wheel groove is calculated, based on the Newtonian heat transfer model and the one-dimensional Fourier heat transfer model. Results show that the cooling rate of the melt during GAC mainly depends on the conduction heat transfer in the wheel groove and the melt thickness. When the thickness of the pure aluminum melt is between 1 and 2.5 mm, the cooling rate can reach 103–104 K s−1, which is much higher than that in CAXTEX (~10 K s−1). It means that GAC is a very effective process in the preparation of non-equilibrium solidification alloys.