Studies on Al-MWCNT MMC surface coating on Aluminium substrates through friction surfacing process

Abstract

Abstract In this study, Aluminium-Multi Wall Carbon Nano Tube (Al-MWCNT) metal matrix composite surface coating was fabricated by using solid state friction surfacing technique on Al substrate. The influence of process parameters on the coating dimensions, integrity and hardness was examined. The optical microscopy studies revealed that the coating integrity with the substrate is good with Trial-2 parameters i.e RPM 2500, Axial Load 700Kg and Traverse Speed 6mm/s. Grain refining due to the dynamic recrystallization was observed in the coating microstructure. XRD studies revealed that the MW-CNTs were distributed in to the coating and no detrimental intermetallic compounds were formed between Al matrix and MW-CNTs except Al4C3. The Scanning Electron Microscopic Studies reveals that the Al metal was severely deformed before forming the coating which is evident from the flow lines. It is further confirmed from the SEM studies that the MW-CNTs were dispersed uniformly within the coating and the nano size was retained in the coating without significant coarsening.