An Examination on Dry Sliding Wear Behaviour of AA7075 Aluminium Alloy Modified with FA/Cu Electro-Discharge Coating

Due to its improved mechanical behaviour, the aluminium alloys play vital role in several industries such as automotive, construction, and aircraft. Nevertheless, usage of aluminium alloys in the sliding applications is very limited due to its poor tribological behaviour. Therefore, it is necessary to enhance the surface and tribological properties of aluminium alloy through the application of appropriate coating materials. In the present research work, the AA7075 aluminium alloy is modified with flyash–copper (FA–Cu) composite coating using electro-discharge coating (EDC). The present paper studied the wear performance of AA7075 coated with FA/Cu using pin-on-disc tribometer. Effect of sliding parameters (applied load, sliding speed, and sliding time) on wear rate (WR) and coefficient friction (COF) is studied through Taguchi method. It is observed that as sliding parameter increases, WR and COF increase. At higher level of sliding time, WR starts to decreases, due to the melting of coating materials. At the lower applied load (15N) and speed (100 rpm), WR is minimum that created abrasion mechanism due to grooving or ploughing. Melting of coating particle was observed at the higher applied load (35N) and speed (300 rpm) which reduces the WR regardless of the sliding time. Different wear mechanisms, including abrasion, oxidation, delamination, and melting, were identified on the surface that had undergone wear.