Development and anti-wear performance of NiCrB coatings with nano graphene and α-Al2O3 particles on Al2024 substrate

This study investigates the tribological behavior NiCrB/nano α-Al 2 O 3 /graphene composite coating fabricated on an Al2024 substrate. Sliding distance and sliding speed were identified as the most significant factors influencing the specific wear rate(Ws). The increase in the load significantly reduced the coefficient of friction (COF), which is attributed to rapid asperity deformation and transfer film formation, leading to the early stabilization of COF. The formation of tribo-oxide layer and adhesive nature wear at higher sliding distance has resulted in lower coefficient of friction. The frictional heat dissipation due to the presence of asperities on the coated surface contributes greatly to the rise in temperature. Statistical analysis revealed that sliding distance and sliding speed contributed 43.11% and 25.56%, respectively, to the variation in specific wear rate, whereas sliding speed contributed 44.90% to the COF. The optimized wear condition (30 N, 600 rpm, and 1100 m) yielded a minimum specific wear rate of 1.183 × 10⁻⁴ mm³ /N·m. The maximum temperature of 121.30°C is reported for the sliding distance of 1500 m. The enhanced wear-resistance of the NiCrB-α-Al 2 O 3 -Graphene coatings is resulted by the stress-homogenization within the coating. These findings offer anti-wear property of NiCrB coating by structural integration of nano-α-Al 2 O 3 and nano-Graphene particles with enhanced surface functionalization, thereby improving its anti-wear performance.