Cailiao Baohu (Jan 2024)
Wear Resistance of Ni+WC Composite Coatings Prepared by SMAT
Abstract
To enhance the microstructure and improve the wear resistance of TA1 titanium alloy，a planetary mechanical ball milling device was used to perform surface mechanical composite reinforcement treatment on TA1 alloy using five types of mixed reinforcing media with Ni and WC powder ratios of 1 ∶1，2 ∶1，3 ∶1，4 ∶1，and 5 ∶1，respectively.The treatment was carried out at the nitrogen atmosphere of 0.05 MPa，and the rotating speed was set at 350 r/min for 8 h.The one-step surface composite strengthening technology of surface mechanical deformation and solid-state coating composite strengthening treatment on TA1 titanium alloy had advantages such as simple process，low energy consumption and flexibility in coating material selection.Results showed that a composite reinforcement layer consisting of Ni+WC coating and a deformation fine-grained zone was formed on the surface of the TA1 titanium alloy.The thickness of the coating zone was approximately 40 μm or more.The composite coating，obtained when the Ni ∶WC ratio was 3 ∶1，was observed to exhibit the fewest internal defects and was continuous and uniform.Under the applied loads of 5 N and 10 N，the friction coefficient for the Ni ∶WC ratio of 3 ∶1 was lower.The friction range was more stable and the duration was longer.The reinforced samples exhibited a lower wear amount under both load conditions compared to the original TA1 sample.Specifically，the strengthened samples with a Ni ∶WC ratio of 3 ∶1 demonstrated superior wear depth and wear amount compared to the other four ratios，hence exhibiting the most outstanding wear reduction effect.The surface mechanical composite strengthening process under this Ni and WC mixed reinforcement medium significantly enhanced the wear resistance of the TA1 titanium alloy surface.The mixed reinforced particle coating exhibited a strong friction-reducing effect，with its wear mechanism primarily being abrasive wear and oxidative wear.
