| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 829552 | Materials & Design (1980-2015) | 2014 | 6 Pages |
•A novel high temperature self-lubricating anti-wear composite coating was fabricated.•Reinforced carbides as well as self-lubricating sulfides were in situ synthesized.•Microhardness of the Ti–6Al–4V substrate was significantly improved.•Friction coefficient and wear rate of the composite coating were greatly reduced.
To enhance the wear resistance and friction-reducing capability of titanium alloy, a process of laser cladding γ-NiCrAlTi/TiC + TiWC2/CrS + Ti2CS coatings on Ti–6Al–4V alloy substrate with preplaced NiCr/Cr3C2–WS2 mixed powders was studied. A novel coating without cracks and few pores was obtained in a proper laser processing. The composition and microstructure of the fabricated coating were examined by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) techniques, and tribological properties were evaluated using a ball-on-disc tribometer under dry sliding wear test conditions at 20 °C (room-temperature), 300 °C, 600 °C, respectively. The results show that the coating has unique microstructure consisting of α-Ti, TiC, TiWC2, γ-NiCrAlTi, Ti2CS and CrS phases. Average microhardness of the composite coating is 1005 HV0.2, which is about 3-factor higher than that of Ti–6Al–4V substrate (360 HV0.2). The friction coefficient and wear rate of the coating are greatly decreased due to the combined effects of the dominating anti-wear capabilities of reinforced TiC and TiWC2 carbides and the CrS and Ti2CS sulfides which have excellent self-lubricating property.
