Effect of graphite particles on physical and mechanical properties of nickel matrix composite

Abstract

The composite materials have effective properties and characteristics for use in most modern and important applications such as space and transportation applications, especially in internal combustion engines as well as applications and marine industries. In this study, Nickel – 5 vol.% Zirconium dioxide composites with 0, 2, 4, 6 and 8 vol. % of graphite particles are prepared by powder metallurgy technique. The samples are pressed at 900 MPa for 1 min after mixing the hybrid composite powders for 15 min by using a mechanical mixer, followed by sintering at 1160 oC for 3 hours. The hybrid composites are characterized by using an optical microscope. The wear test under dry sliding conditions was performed under various loads of 5, 10, 15 and 20 Newton and at a fixed sliding distance of around 1810 m. It is found that increasing graphite content results decrease in bulk and apparent densities in contrast with total porosity, apparent porosity, and water absorption. Alternatively, the increasing volume fraction of graphite particles improves the micro-hardness, diametral compressive strength and wear resistance till an optimum value up to 4 %, then severely reduction is observed. Whereas the wear resistance decreased by increasing the applied loads for all reinforcement content. The results, in conclusion, reveal that the hybrid composites at 4 % graphite particles relatively have high mechanical and wear properties, and it could be considered a suitable because of high corrosion resistance in our daily life applications.