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TECHNICAL ARTICLE—PEER-REVIEWED

Sliding Wear Behaviour of Nickel-Coated Short Fibre-Reinforced Al7075 Composites Nithin Kumar . M. D. Kiran . S. S. Sharma . B. Ravikiran Kamath . R. K. Veeresha

Submitted: 16 February 2020 Ó ASM International 2020

Abstract In the present study, Aluminium-7075 alloy is reinforced with nickel-coated short carbon fibres in the form of short fibre. These composites were prepared by stir casting method with 2, 4, 6 and 8 wt.% of nickel-coated carbon fibres. Wear resistance of aluminium alloy and its composites were analysed according to the ASTM standards. The experiments were conducted using pin-on-disc wear test and rig wear test method with different loads. From the wear test, it was found that aluminium composites with 8% nickel-coated carbon fibre rate of wear are minimum. Worn and fractured surfaces of cast aluminium alloy and the developed composites are analysed by SEM. The test results reveal that the wear resistance of the prepared MMCs improves with the addition of carbon fibre. Keywords SEM

Al7075 alloy  Pin on disc  Wear resistance 

N. Kumar (&)  B. Ravikiran Kamath  R. K. Veeresha Department of Mechanical Engineering, NMAMIT, Nitte 574110, India e-mail: [email protected] M. D. Kiran Department of Mechanical Engineering, BMS Institute of Technology and Management, Bengaluru, India S. S. Sharma Department of Mechanical and Manufacturing Engineering, MIT, Manipal 576104, India

Introduction Aluminium and its alloys are known for excellent corrosion resistance as well as good mechanical properties. In terms of wear properties, they are poor. Tribological applications like pistons, components of brake-system, engine blocks, wear resistance components and other various aircraft, and defence equipment’s [1]. Metal matrix composites are prepared using aluminium and its alloys to develop newer material to achieve the better tribological properties [2–5]. Hence, requirements for enhancements in wear resistance and service loads of materials in all these applications have forced researchers to develop and synthesise aluminiumbased composites. Silicon carbide, alumina, titanium carbide and fly ash improve the strength, hardness and wear resistance of the composites. Problems are encountered during machining of metal matrix composites due to the addition of hard dispersoids to these composites. Matrix alloy has higher surface finish when compared with the hard-reinforced metal matrix composites. Also, the thermal and electrical conductivity of aluminium is changed by the addition of ceramic reinforcements. Reinforcement also influences machinability index [6]. In the case of Al6061 reinforced with TiO2, it was observed that composites exhibit lower wear coefficient and better hardness as compared with the matrix alloy [7]. The volumetric wear loss is high because of increased loads and sliding distances, but the coefficient of wear is low in both matrix alloy and its composites. The high strength aluminium alloys Al7010, Al7009 and Al2024 reinforced with SiC particles exhi