In order to enhance the surface properties of GCr15 bearing steel, a TiAlCN coating with a low friction coefficient, high hardness, and excellent adhesion was fabricated. The TiAlCN multilayer coating was deposited onto the GCr15 bearing steel surface using magnetron sputtering technology, and optimal coating parameters were achieved by adjusting the number of layers, sputtering power of the graphite target, and coating duration. The experimental results showed that adding Cr/CrN as a transition layer between GCr15 bearing steel and TiAlCN significantly improved multiple properties of the coating. Adding carbon atoms caused TiAlN to dissolve into a TiAlCN structure, enhancing multiple properties of the coating. With the increase in the sputtering power of the graphite target material, the hardness, friction, and wear performance of the coating showed a trend of first increasing and then decreasing. The hardness of the coating gradually increased with time, and the friction coefficient and wear amount first decreased and then increased. When the sputtering power of the graphite target material was 100 W and the coating time was 4800 s, the coating performance was optimal. The hardness was 876 HV, the friction coefficient was 0.42, the wear amount was 1 × 10⁻⁴ g, and the wear rate was 2.8 × 10⁻⁶ g/m·N under optimal process parameter conditions.

The main focus of this work is the successful deposition of hard and wear-resistant TiAlCN coating on the surface of GCr15 bearing steel by means of magnetron sputtering technology. The phase composition of the chromium nitride transition layer was monitored by precisely controlling the nitrogen (N₂) flow rate to strengthen the bonding between the TiAlCN coating and the GCr15 bearing steel surface. It was found that coating performance reached the optimal state at a N₂ flow rate of 40 sccm, yielding a hardness of 23.3 GPa, a friction coefficient of only 0.27, and a wear rate of 0.19 × 10⁻⁸ mm³/N·m.