Tensile Strength of Squeeze Cast Carbon Fibers Reinforced Al-Si Matrix Composites

Abstract

Squeeze casting is a pressure casting process in which molten metal is solidified under the direct action of a pressure. In squeeze casting, the relationship between the process parameters and the quality of the squeeze cast components is not fully understood; thus the need for more studies in this area of technology for better understanding of the process. The present work encompasses studying the effect of direct squeeze casting process parameters on the production of (3 and 20%) volume fraction carbon fibers (CF) reinforced Al-Si matrix composites. The evaluated process parameters are squeeze pressure in the range (7.5-53) MPa, die preheating temperature (100,200,300)°C, pouring temperature (700,780)°C, squeeze time (30 sec.), and delay time (5 sec.). The results show a good distribution of the matrix between the carbon fibers when using higher casting pressures of (38 and 53MPa), lower pouring temperature of (700°C) and lower die temperatures of (100 and 200°C). Increasing the carbon fibers volume fraction had led to increasing the tensile strength. The using of higher pressure (53MPa), lower pouring temperature (700°C), and lower die temperature (200°C) have increased the ultimate tensile strength of the CF/Al-Si composites to (183MPa) when compared to that of the nonreinforced alloy which was (168MPa) because of the increased bonding, decreased shrinkage defects and fibers degradation based on the results. Also, UTS is increased at P=38MPa, Tp=700°C, and Td=100°C.