Cu/SiC Functionally Gradient Materials (FGMs) and Al-based metal matrix composites were fabricated by the cold pressing and pyrolysis of their metal powders with organosilicon preceramic polymers, such as polymethylsilane (PMS) or polycarbosilane (PCS). The changes in physical properties of the Cu/SiC FGMs result from gradient changes in chemical composition. In order to understand the change in the properties, the microstructure and chemistry of Cu/SiC FGMs have been investigated using scanning electron microscopy (SEM), analytical transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDXS). The microstructure and chemistry of the reinforcing phases present in the Al-based metal matrix composites were investigated using analytical TEM and EDXS in order to understand the chemical reaction of the Al powders with PMS preceramic polymer. These microstructural results support the hypnosis that when the metal powders and preceramic polymers (such as PMS and PCS) were heated, the preceramic polymers decomposed first to create SiC and carbon ceramics, and on further heating the SiC and carbon ceramics reacted with their metals to generate the reinforcing phases dispersed in the matrices.
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