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The present work aims to improve the microstructure and hardness relatedproperties of age hardened Al6061-SiC reinforced composites produced by a two stage stir casting method. Three composites with2, 4, and 6wt. % (35-40μm) of SiC reinforcement are subjected tomicrostructural examination and hardness test at different locations to analysethe uniform distribution of the reinforcements in the matrix. As-castcomposites are solution-treated at 558°C, followed by an aging treatment conducted at 100, 150, and 200°C, during which peak hardness values are noted. The peak agedsamples are subjected to hardness and wear tests. In line with the objectives, ranges from 80-100% and 120-145% additional increase in hardnessvalues are observed over as-cast alloy during the aging treatment conducted at 100, 150 and 200°C, respectively. Lower temperature aging showssubstantial improvement in hardness and wear resistance over high temperatureaging in each respective group. Alsohigher weight percentages of reinforced composites show excellent wearresistance, due to the presence of eroded iron particles fromthe counter surface which is regarded as a beneficial effect during the wear test. The presence of SiC particles provides more sites for the nucleation of fineprecipitates. These fine precipitates hinder the movement of dislocation andthus increases hardness as well as wear resistance after the precipitation hardening treatment. |
