Study of Dispersoid Content and Chill Effect for Improved Mechanical Properties of Aluminum Alloy Composite
International Journal for Ignited Minds
The present investigation is aimed at studying the effect of dispersoid content and effect of chill on microstructure and mechanical properties of aluminum alloy (LM-13) hybrid metal matrix composites reinforced with Magnesium (Mg) and is fixed 16.3wt% with Silica (Sio2). The size of the Silica (Sio2) particles varies from 50 to 80 µm and amount of addition varies from 1.63 to 4.91wt% in steps of 1.63wt%. By using chills of different material with different volumetric heat capacity (VHC), the
... pacity (VHC), the effect on the microstructure evolution was examined. Stir casting process was used to produce chill cast aluminum alloy-magnesium-silica particulate composites in moulds containing various chills of copper, steel, and silicon carbide to accelerate the solidification. The fabricated composites were tested for their hardness and ultimate tensile strength properties according to ASTM standards. The effect of chill and reinforcement characteristics was presented and compared with the hybrid composite without chill material. Microstructural studies of the chill cast composite developed indicate that there is uniform distribution of the reinforcement in the matrix alloy with significant grain refinement and retention of residual porosity. Mechanical properties reveal that the presence of silica particulates has improved significantly the ultimate tensile strength and hardness as compared against the matrix alloy. The results confirm the positive relationship between mechanical behavior and the dispersiod content. The copper chill cast composite with 81.96wt% Lm-13, 16.39wt% Mg and 3.27wt% Si02 was found to increase mechanical properties.