Influence of Flyash & Silicon Nitride on Mechanical & Tribological Properties of Aa 7075 Hybrid Composite

Abstract

The main objective of this research work is to study the effect of Silicon Nitride (Si3N4) and Flyash on the mechanical and tribological properties of AA 7075 hybrid composite. The Stir casting technique has been used for the fabrication of composite material. sAA 7075 were reinforced with 2 wt. % of Silicon Nitride and 2.5, 5, 7.5 wt. % of Flyash. Pin-on-disc equipment is used to evaluate the wear rate of the base alloy and hybrid composite. Dry sliding wear test were performed with the contact load which is varied by 10, 20 & 30 N. Sliding velocity is varied by 1, 1.5 and 2 m/s. Sliding distance is kept constant at 1000 m. The Scanning Electron Microscope (SEM), Energy Dispersive X Ray Spectroscopy (EDAX) and X-ray diffraction (XRD) were used for the characterization of the composites. The maximum hardness of 173 HV is achieved for 5 wt% Flyash and 2 wt% of Silicon Nitride addition. The percentage increase in hardness is 155 % above the base metal. AA 7075 with the 5 wt % reinforcement of Flyash shows the minimum wear rate. With respect to the base the wear rate is reduced by 59 %.