Characterization of thermal cycles and investigation of thermal expansion behavior of the Al-4%Cu composite alloy reinforced by SiC particles

Although Al/SiC composite has attracted much attention of the researchers، no due attention has been paid so far to its physical properties particularly its dimensional stability. Therefore، the objective of this research is to investigate the thermal-physical properties of these composites and the presented models of these properties. Initially، the Al/4%Cu alloy was prepared by mechanical alloying، and then the aluminum composite was synthesized with different percentages of silicon carbide (with different particle sizes). To characterize the composite hardness and density tests were performed. Thermal test on the Al-4%Cu/SiC composites revealed that with increase of volume fraction of SiC particles up to 25%، thermal expansion coefficient of the composite has decreased linearly، which indicates the presence of ceramic particles with very low thermal expansion coefficient in the composite. Also، these results reveal that with increase of temperature up to 500°C، thermal expansion coefficient has increased up to 20. 6 for the composite with 15% of reinforcement particles، although this increase is not linear. In order to investigate the effect of the reinforcement particles size on thermal expansion coefficient of the Al-4%Cu/SiC composite thermal tests were performed which indicated that the reinforcement particles size has no conspicuous effect on thermal expansion coefficient of the composite but causes a thermal strain of 0. 8% in the composite to some extent.