Magnesium Matrix Composites, (sic_paz91d) Preparation Process

The SiCp/AZ91D composites were fabricated with high joining ratio, uniform distribution and low pore ratio by adjusting the joining means of SiCp and the parameters of process for the localization of recent stirring-casting technologies. Meanwhile deforming tests were performed for SiCp reinforced Mg based composites prepared by stirring-casting process after equal channel angular pressing(ECAP) to eliminate the defects in the structures and obtain the uniform distribution of SiCp. The structures of Mg based composites and fracture surface were observed and analyzed by optical microscope and scanning electron microscope after ECAP. The results show that the casting defect such as pores were eliminated, the size of grains was be reduced and the uniformity of particle was improved after ECAP. The connection of matrix and particles, the harm accommodation to SiCp also were improved; SiCp masses were the main cause of fracture of the composites with tenacious fracture of the matrix alloy companied with some disconnection between particles and matrix and the cross-grain fracture exists. After ECAP, principal part was tenacious fracture of the matrix with little quantitative cross-grain fracture in the structures and disconnection between particles and matrix was the main form in the area of dense distribution of SiCp.