Preparation of High Strength Mo(Si, Al)2-SiC Composite by Melt Infiltration Process

The Mo(Si, Al)₂-SiC composite was prepared by infiltrating melted aluminum into MoSi₂+C compacts at 1350°C, and the microstructure and mechanical property of this composite were analyzed. The results showed that the phases of these composite are Mo(Si1-x, Alx)₂ and SiC, and a small amount of Mo5Si3C and Al. Increasing the value of x, the amount of Mo5Si3C and Al phases decrease and even disappear gradually. The microstructure of this composite is sheet-like Mo(Si, Al)₂ with needle-like SiC distributed in its gap, and parts of SiC are whisker-like. When x = 0.2, the bending strength of the composite reaches the maximum, which was 770 MPa. The bending strength of designed composite prepared by melt infiltration in this study is better than that of the composite prepared by hot pressing reported in literature.