Investigation on mechanical, wear, and machining characteristics of Al 7075/MWCNTs using the liquid state method

Abstract

In the present research work, an attempt has been made to fabricate the aluminum metal matrix composite by the stir casting method. Aluminum 7075 alloy is used as a matrix which is reinforced with multi-walled carbon nanotubes (MWCNTs) with varying percentage (0 wt.%, 1.0 wt.%, 2.0wt.%, and 3.0 wt.%). Experiments were carried out to analyze microstructure, mechanical, tribological, and machining characteristics such as microhardness, tensile strength, wear rate, coefficient of friction, material removal rate (MRR), and surface roughness (Ra). Also, the samples were studied under a scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and X-ray diffraction analysis (XRD) to investigate the dispersion, chemical composition, and elemental analysis of multi-walled carbon nanotubes in Al 7075. The microscopic study of metal matrix composite samples shows a good dispersion of MWCNT into Al 7075. Results show that the microhardness and tensile strength increase by 6% and 25%. The wear rate and coefficient of friction of composites are decreased by 39% and 48% at a sliding speed of 3 m/s. In addition, the metal removal rate decreases by 40% and the surface roughness enhanced by 38% respectively.