Ni60-WC coatings with different WC contents on the bucket tooth substrates were pre- pared using laser cladding technology. Their abrasive wear properties were assessed using the dry sand rubber wheel test system. The substrate and the hard-facing layer were tested for comparison. The results showed that the hardness of the Ni60-WC coatings increased with the increase in WC content. The wear resistance of the bucket tooth substrate was greatly improved by hard-facing and laser cladding Ni60-WC coatings. The wear rate of the hard-facing layer was reduced to 1/6 of that of the tooth substrate. The wear rate of the laser cladding coatings with 20–40 wt.% WC was similar to that of the hard-facing layer. It is worth mentioning that the wear rate of the coatings with 60–80 wt.% WC was only 1/4 of that of the hard-facing layer. Micro-cutting with surface plastic deformation was the main wear mechanism of the substrate to form narrow and deep furrows. The wear mechanism of the hard-facing layer was mainly plastic deformation with a wide groove, and the surface cracks promoted the removal of the material. The removal of the binder phase caused by micro-cutting was the main wear mechanism of the laser cladding Ni60-WC coatings. However, the hard phase of WC hinders micro-cutting and plastic deformation, which improves the wear resistance of the coating.

The effects of titanium (Ti) ion-implanted doses on the chemical composition, surface roughness, mechanical properties, as well as tribological properties of 316L austenitic stainless steel are investigated in this paper. The Ti ion implantations were carried out at an energy of 40 kV and at 2 mA for different doses of 3.0 × 10¹⁶, 1.0 × 10¹⁷, 1.0 × 10¹⁸, and 1.7 × 10¹⁸ ions/cm². The results showed that a new phase (Cr₂Ti) was detected, and the concentrations of Ti and C increased obviously when the dose exceeded 1.0 × 10¹⁷ ions/cm². The surface roughness can be significantly reduced after Ti ion implantation. The nano-hardness increased from 3.44 to 5.21 GPa at a Ti ion-implanted dose increase up to 1.0 × 10¹⁸ ions/cm². The friction coefficient decreased from 0.78 for un-implanted samples to 0.68 for a sample at the dose of 1.7 × 10¹⁸ ions/cm². The wear rate was slightly improved when the sample implanted Ti ion at a dose of 1.0 × 10¹⁸ ions/cm². Adhesive wear and oxidation wear are the main wear mechanisms, and a slightly abrasive wear is observed during sliding. Oxidation wear was improved significantly as the implantation dose increased.

Coating on the surface is one of the main ways to improve the corrosion resistance and wear resistance of materials. In this work, the corrosion, erosion, and wear resistance of WC–10Co4Cr coating and 27CrMoV substrate were compared by simulating the actual working conditions of the drill pipe. The simulation results show that the most serious corrosion occurred at the pipe body and the dominating erosion arose at the pipe joint closing to the inlet of the flow field. WC–10Co4Cr coating has excellent protection to 27CrMoV substrate, resulting in a 400 mV increase in corrosion potential, a two-orders-of-magnitude decrease in the corrosion current, and four times the improvement of the impedance value. The erosion resistance of the WC–10Co4Cr coating increased to more than 30% higher than that of the 27CrMoV substrate. The friction coefficient of the WC–10Co4Cr coating was much lower than that of the 27CrMoV substrate, and the wear resistance of the coating was higher than that of the substrate.

Ultrafine tungsten carbide-nickel (WC-Ni) cemented carbides with varied fractions of silicon carbide (SiC) nanowhisker (0–3.75 wt.%) were fabricated by spark plasma sintering at 1350°C under a uniaxial pressure of 50 MPa with the assistance of vanadium carbide (VC) and tantalum carbide (TaC) as WC grain growth inhibitors. The effects of SiC nanowhisker on the microstructure and mechanical properties of the as-prepared WC-Ni cemented carbides were investigated. X-ray diffraction analysis revealed that during spark plasma sintering (SPS) Ni may react with the applied SiC nanowhisker, forming Ni₂Si and graphite. Scanning electron microscopy examination indicated that, with the addition of SiC nanowhisker, the average WC grain size decreased from 400 to 350 nm. However, with the additional fractions of SiC nanowhisker, more and more Si-rich aggregates appeared. With the increase in the added fraction of SiC nanowhisker, the Vickers hardness of the samples initially increased and then decreased, reaching its maximum of about 24.9 GPa when 0.75 wt.% SiC nanowhisker was added. However, the flexural strength of the sample gradually decreased with increasing addition fraction of SiC nanowhisker.