Investigations on Microstructure, Mechanical, Thermal, and Tribological Behavior of Cu-MWCNT Composites Processed by Powder Metallurgy

B Stalin,Alagar Karthick,M Ravichandran,S Karunakaran,G T Sudha,Murugesan Bharani,M Meignanamoorthy,Sami-Ullah Rather

doi:10.1155/2021/3913601

Abstract

Copper (Cu) metal matrix composite (MMC) was developed with multiwall carbon nanotubes (MWCNT) as reinforcement by using powder metallurgy (PM) technique. The composition of the composites is Cu, Cu-4 wt% MWCNT, Cu-8 wt% MWCNT, and Cu-12 wt% MWCNT. The Cu and MWCNTs were blended for 6 hours in a ball mill and compacted at a 6 ton pressure to form green compacts using a 10 ton hydraulic press. Using a tubular furnace, the heat was applied at 900°C for 1.5 hours to impart strength and integrity to the green compacts. Milled composite blends were studied to analyze its characterization through SEM and EDAX analysis. Characterization studies such as SEM and EDAX confirm the presence and even dispersion of Cu and MWCNT constituents. The relative density, hardness, and ultimate compressive strength have been studied, and a remarkable improvement in properties has been obtained by the inclusion of MWCNTs. The composites reinforced by 8 and 12 wt% MWCNT were recorded with low thermal conductivity than the Cu composite reinforced by 4 wt% MWCNT. A wear study was analyzed using Taguchi technique for determining the effect caused by the wear test parameters and MWCNT content on wear rate. The optimized parameter that contributes minimum wear rate was identified as 12 wt% MWCNT content, 10 N applied load, 2 m/s sliding velocity, and 500 m sliding distance. Based on the obtained results, it could be understood that the produced composites can be utilized for various applications like relay contact springs and switchgear, rotor bars, and bus bars.

Highlights

Composite fabrication generally incorporates combining the reinforcement with matrix and wetting them
In this study, it is clear that thermal conductivity of copper matrix is superior than multiwall carbon nanotubes (MWCNT) particle; this is the most important reason to beg off in the composite thermal conductivity
From the main effect plots, the optimized parameter levels that contribute minimum wear rate were identified as 12% MWCNT content, 10 N applied load, 50

Summary

Introduction

Composite fabrication generally incorporates combining the reinforcement with matrix and wetting them. Matrix-reinforcement combines collectively into an inflexible material [1] Because of their superior mechanical, tribological, electrical, and thermal properties, metal matrix composites (MMC) found their widespread applications in ever-growing fields such as aerospace, automotive, and structural [2, 3]. Carbon nanotubes (CNTs) are such a reinforcement that is well known for its one-dimensional quasicarbon structures with greater aspect ratio and better electrical, thermal, and mechanical properties. The strength of the matrix materials has been found to get improved in association with CNT reinforcements, and the CNT reinforced composites are extensively used in automotive and aerospace applications [15, 16]. Wang et al [24] investigated the properties and enhancements of Cu-CNT composites’ interfacial interaction and found that yield strength, plasticity, and electrical conductivity were improved with the increase in CNT reinforcement. The impact of MWCNT weight percentage and the wear test parameters such as load applied, sliding distance, and sliding velocity on the wear rate of Cu-MWCNT composites was analyzed using Taguchi analysis, and the optimized parameter levels for minimum wear rate were identified

Experimental Details

Results and Discussion

Taguchi Analysis

Conclusions