Study of hardness and tensile behaviour of Fe2 O3 reinforced Al-Cu alloy metal matrix composites by stir squeeze casting

Abstract

The processing of metal matrix composites (MMCs) by casting process is a very promising way of manufacturing near net shape composites at relatively low cost. The liquid metallurgy stir, squeeze casting technique has the characteristics such as fine microstructure as a result of rapid cooling, low porosity and good bonding between the particles and base alloy. Hematite is a common iron oxidewith a formula called Fe₂O₃ and has been widespread in rocks and soils. Hematite forms in the shape of crystals through the rhombohedral lattice system, and it has the same crystal structure as lmenite and corundum. The paper presents the results of experimental investigation on mechanical properties of Fe₂O₃ particle reinforced aluminium metal matrix composite. The influence of 3, 6, 9 and 12wt% Fe₂O₃-p reinforced on mechanical properties was examined and the outcome of the tests revealed that hematite particles can be successfully used as a reinforcement material and it does not deteriorate the properties. The increase in hematite particle percentage and high squeeze pressure resulted in high density of the compact, thereby increasing compression strength, tensile strength and hardness of the composite. The results also showed that for the same base alloy the squeeze cast shows higher hardness, tensile and compression strength compared to the gravity cast base alloy. Squeeze cast composites exhibit higher hardness tensile and compression properties by increasing weight percentage of reinforcements. The microphotographs of squeeze cast samples shows uniform dispersion of the reinforcements in MMCs with good bonding between the matrix and reinforcement.