Study of Various Factors and the Protective Atmosphere on Aluminum Alloy Properties in Casting Process With Cooling Slope Method

The cooling slope (CS) method is one of the forming processes in semi-solid state that the molten alloy with a suitable pouring temperature is poured on a cooling slope for achieving fine and non-dendritic structure. In this method, the parameters such as cooling slope length and angle, pouring temperature and rate, mold temperature were affected on microstructure and morphology of primary phases. In this paper, at first discusses the effect of these parameters on the final microstructure of A356 aluminum alloy and the effective equations in cooling slope process and their influence on the grain size diameter and hardness were examined. It was found that both cooling slope length and pouring rate on grain size diameter and hardness are more effective than other factors. The advantages of using the protective atmosphere with tests such as XRD and ultrasonic test are studied. The results shown that with using the protective atmosphere in cooling slope method don’t have a significant effect on the grain size diameter. However, the strength and ductility of the alloy is increased 17.8 and 28.1% respectively, due to the reduction in the porosities and inclusions.