Study on microstructure and tribological property of aluminium-nickel composites fabricated by bottom pour stir casting

Abstract

The present research explores the mechanical and tribological behaviour of Ni-reinforced aluminium composite. The aluminium alloy-1050 series has generally poor wear resistance. To enhance the wear resistance, a bottom pour stir casting method has been used to reinforce the hard Ni particles in the aluminium alloy at different weight percentages (6, 12, 18 wt%). As per the microstructural analysis, the manufactured base and composite materials have a polycrystalline structure. The peritectic reaction creates a hard intermetallic Al3Ni phase in the composites in terms of chemical reactions between the aluminium and Ni. XRD analysis has demonstrated the presence of the Al3Ni phase in the composites. The Al3Ni phase’s strong atomic bonding has enhanced the work of adhesion, hardness, and wear resistance. The dry sliding wear behaviour of the cast-AA and composites has been examined by a pin-on-disc instrument at different loads (20 and 40 N) against a hardened EN31 steel disc. The worn surface SEM images resulted in the following wear mechanisms: ploughing, adhesion, delamination, and abrasion. The CoF and wear debris size have been increased by increasing the load from 20 N to 40 N.