Fabrication and characterization of squeeze cast A413-CSF composites

A413 aluminum matrix composites reinforced with short carbon fibers (CSFs) were produced using a combination of vortex and squeeze casting processes and the effects of reinforcement volume fraction and reinforcement coating on density, porosity, reinforcement distribution and mechanical properties of the produced composites were studied. The results showed that increasing the volume fraction of CSFs led to decreased density and increased porosity of the cast composites. Distribution of uncoated CSFs in the matrix of the reinforced samples was poor and most of the fibers were in agglomerated bundle form. Utilization of coated CSFs resulted in a rather uniform distribution of the reinforcement in the matrix. Mechanical properties of squeeze cast composites fabricated using uncoated CSFs improved by increasing the reinforcement volume fraction up to 2% and decreased beyond it. Mechanical properties of the squeeze cast composites fabricated using coated CSFs improved steadily by increasing the reinforcement volume fraction up to 3%. Ultimate tensile strength and hardness values of the composites reinforced with 3 vol% coated CSFs increased by more than 100% and 60%, respectively, in comparison with those of the monolithic cast sample.