SiC Fiber Reinforced SiC-Si Matrix Composites Prepared by Melt Infiltration (MI) for Gas Turbine Engine Applications

General Electric (GE) has developed silicon carbide fiber reinforced SiC-Si matrix composites by silicon melt infiltration (MI) for use in gas turbine engine applications. This paper focuses on a process based on tow prepreging and lamination of unidirectional tapes. Silicon melt infiltration yields a fully dense, near net shape composite with a relatively high thermal conductivity, actually higher than many superalloys at temperatures up to 800°C, and a high proportional limit, or matrix cracking stress. Room and elevated temperature mechanical properties of the composite are presented. Following exposure to various simulated turbine environments this material shows relatively good retention of strength and toughness. The fabrication of turbine shroud and combustor liner components for high pressure combustion rig testing is also described.