Microstructure and orientation relationships of Mg alloy matrix composite reinforced with SiC whiskers and B_4C particles

摘要

The microstructure and orientation relationships of ZK60A magnesium alloy matrix composite reinforced with SiC whiskers and B_4C particles have been studied by means of transmission electron microscopy and high-resolution electron microscopy. MgO nanocrystalline particles are formed at SiC/Mg interfaces with a cube-on-cube orientation relationship with SiC whiskers. MgB_2 nanorods are formed near the B_4C particles. Two types of orientation relationships between the SiC whisker and Mg are observed, which are [111]_(SiC)‖[0001]_(Mg) and (022)_(SiC)‖(H20)_(Mg), and [111]_(SiC)‖[1120]_(Mg) and (022)_(SiC)‖(0112)_(Mg). Geometrically, [111]_(SiC)‖[0001]_(Mg) and (022)_(SiC)‖(1120)_(Mg) is more favorable than [111]_(SiC)‖[1120]_(Mg) and(022)_(SiC)‖(0112)_(Mg).