Powder Injection Molding of 20-40 Vol. Silicon Carbide Particulate- Reinforced Aluminum Composites

摘要

Effects of 20-40 vol.% SiC_p additions on microstructure and hardness of aluminum composites have been investigated in this research. The composites were produced via powder injection molding at 170°C followed by solvent debinding and sintering at 700-820°C. After sintering, composite microstructures and properties were influenced by SiC_p additions and sintering temperatures. Higher SiC_p additions required higher effective sintering temperatures. Furthermore, increasing SiC_p content promoted SiC_p agglomeration along aluminum grain boundaries and caused SiC_p pull-out during metallurgical preparation. This resulted in higher porosity observed from the sintered microstructures. Variation in macro Vickers hardness values were obtained due to opposing effects of increasing contents of SiC_p and porosity. Optimum hardness values were obtained when sintering was carried out at 740, 780 and 800°C for 20, 30 and 40 vol.% SiC_p additions respectively.