Analysis of mold flow and microstructures of die casting in Al alloy/SiC(p) composites

The report involves a study of the microstructure of tensile, impact and three-point bending samples of aluminum alloy/SiC_(p) composites produced by die casting. The results show that in impact samples, 80 m SiC particulates cluster along the left and right edges of the section vertical plane with the notch plane, and near the notch. In tensile and three-point bending samples, they were distributed uniformly in the matrix. Furthermore, porosities occurred near the notch in the impact samples. The 80 m SiC particulates will undergo settling in the shot biscuit. There exist arc and irregular shapes in the clustering section of the particulate. The dendrite arm spacing (DAS) is larger in this section. From the shot biscuit to the bending section of the sprue; the quantity of SiC particulate is less. The SiC particulate is clustered in the protrusive region where the injector pins are situated. We can decrease the porosity of die casting samples effectively by designing the overflow well in a wave shape. We can prevent the melt from adhering to the surface of the mold cavity, thermal cracking on the surface of die casting samples and wear on plungers using electroless nickel plating on the SiC particulate.