Need for optimization of graphite particle reinforcement in ZA-27 alloy composites for tribological applications

► Wear behavior of ZA-27/graphite composite improves with various percentage of graphite particle reinforcement. ► The thermal conductivity and thermal diffusivity decreases with increase in graphite content and also with increase in test temperature. ► Specific heat reduces slightly after addition of graphite particles. ► Damping improves with the addition of graphite particle at ambient and increases with increase in temperature. ► All the above parameters were observed to optimize the graphite reinforcement. The objective of present work is to investigate the effect of macroscopic graphite particles on mechanical, wear and thermal behavior of ZA-27 alloy composites. Compo casting technique was used to prepare the composites in which the graphite particles were used to reinforce ZA-27 alloy. Wear tests were conducted using pin on disc apparatus under unlubricated conditions at various load and speeds. Damping capacity, stress–strain and amplitude behaviors were studied using dynamic mechanical analyzer at various temperatures from ambient to 300 °C. Thermal conductivity and diffusivity were found using laser flash apparatus and specific heat values were found using simultaneous thermal analyzer. It was observed that the tribological property improves with the addition of graphite particle. However with observations of other parameter, it is clear that reinforcement percentage need to be optimized based on application requirement in order to have better performance and the composites can be used as structural material in various applications like bearings and thermal control functions.