Effects of process parameters on the properties of squeeze-cast SiCp-6061 Al metal-matrix composite

The effects of process parameters on the properties of squeeze-cast high reinforcement volume-fraction SiCp-6061 Al metal matrix composite (MMC) have been examined. The process parameters included cooling rate, reinforcement particle size, addition of silica binder, and solution treatment temperature. The properties studied were flexure strength, microstructure, variation of hardness, solute content gradient, and aging behavior. It was found that water cooling improved the flexure strength and hardness of MMC significantly when compared with furnace-cooled MMC. For the same volume fraction of reinforcement, lowering the average particle size from 85 to 14 μm increased the flexure strength and hardness of the MMC greatly. A solution treatment temperature very close to the eutectic point was found to improve the strength. Mechanisms leading to the above-mentioned effects and suggestions are discussed.