Low-Cost Molybdenum Disilicide Matrix Composites

点击翻译按钮获取中文摘要

Carbon fiber-reinforced in SiC whisker-reinforced molybdenum disilicide (MoSi2) matrix composites have been identified as excellent candidates for high temperature structural applications in oxidizing environments. However, the room temperature fracture toughness and high temperature yield and creep strength of these materials can still be drastically improved, and processing issues must be resolved. In this Phase I proposal, Ultramet proposes to demonstrate the feasibility of several fabrication methods for MoSi2 matrix composites that are capable of eliminating the major sources of processing flaws and of greatly increasing process repeatability and cost-effectiveness, while enhancing mechanical properties. MoSi2-coated whiskers and MoSi2-infiltrated carbon fabric will be fabricated by chemical vapor deposition (CVD) with several alloy microstructures, followed by properties measurements. These results will be compared to available data for SiC/MoSi2, C/C, and C/SiC materials, and an analysis of cost, reliability, fabricability, and performance will be conducted. The most immediate application for MoSi2 composites for engine hot section components, and industrial furnace equipment is another potential market. Also, with upcoming EPA requirements for drastically reduced emissions, new materials such as MoSi2 will be required in much greater quantities to withstand the higher temperatures associated with clean-burning, low-Nox technology.