Effect of Pouring Temperature and Partial Remelting on Microstructure and Wear Properties of A390 Alloy in Slope Cooling Casting

Slope cooling casting is one of the production methods in semi-solid state. Semi-solid processes led to reduce gas porosity and shrinkage and modify the structures. In this research, the effect of pouring temperature in slope cooling casting process and partial remelting temperature on microstructure and wear properties of Al-A390 alloy have been investigated. In this regard, casting was performed at 5 different pouring temperatures on a sloping surface with the constant length of 500 mm, angle of 45° and mold temperature of 450°C. Then, the partial remelting process was carried out at 3 different temperatures with a constant time. The results show that the suitable condition in view of the particle non-dendritic and the high hardness is achieved at the temperature of 590°C on the slope cooling with the length of 500 mm and the angle of 45°. In examining of the effect of the partial remelting temperature, the sample kept at temperature of 545°C for 30 minutes, compared to samples with partial remelting temperature of 555°C and 565 °C, has a finer and more uniform grain structure. So that, the hardness and the weight loss at this temperature were obtained about 130 HB and 0.0193 gr. The hardness and wear resistance of this sample in comparison to sample without partial remelting increased 30 and 43 percent, respectively.