A Comparative Investigation on the Tribology and Microstructure of MWCNT Reinforced h-AMMC Sintered by Conventional and Microwave Heating Route

Abstract

In the current work Al-alloy, AMMC and MWCNT-reinforced hybrid AMMCs have been fabricated successfully with the help of Microwave Hybrid Heating as well following conventional route of powder metallurgy. This was followed by a detailed investigation on the microstructural, physical, mechanical and functional behavior of the fabricated materials. Different metallurgical and mechanical characterization techniques such as optical microscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), Vickers’s micro hardness and porosity measurements have been used. EDS point and area mapping, XRD and Raman spectroscopy has been carried out for the compositional analysis. The tribological characteristics i.e. wear and friction, of fabricated Al, AMMC and h-AMMC has been studied by using a Pin on Disc sliding wear Tribometer. Graphical analysis of coefficient of friction of h-AMMC has been analysed using Windcom software for both conventional as well as microwave technique. The results reveal the viability and significance of microwave material processing over conventional methods for the fabrication of AMMC. h-composite exhibits higher hardness than Al matrix and Al+SiC composite. The results of compositional analysis indicated that the intensity of formation of different oxide phases such as Al2O3, Cr2O3, MnO2 and CuO in conventional sintering process is significantly higher as compared to microwave sintering process. From wear study, it has been found that wear and friction properties of h-composite are better than Al matrix and Al+ SiC composite. However, the nature of distribution as well as % of MWCNT is found to have significant effect on the tribological characteristics. Further, it has been found that h-composite with a composition (Al+15%SiC+1%MWCNT) significantly enhances the tribological performance in different operating conditions.