Anti-wear Performance of WC-10Co4Cr Coating in Water-Based Drilling Fluid with Different Contents of Filtrate Reducer and Bentonite Clay

To improve the anti-wear performances of drilling tools in geological prospecting, WC-10Co4Cr coating spayed via high-velocity oxygen-fuel (HVOF) was prepared on the 1045 steel substrate. Tribological behaviors of WC-10Co4Cr coatings in water-based drilling fluids with different contents of filter reducer and bentonite clay was evaluated by a CSM ball-on-disc tribometer. The results showed that high content of the filtrate reducer was beneficial to reducing coefficients of friction (COF) and improving anti-wear performance of WC-10Co4Cr coatings during the sliding. It is due to the formation of tribofilms with large thickness. However, high content of bentonite clay increased COF and decreased the wear resistance of WC-10Co4Cr coating during the sliding, which resulted from the abrasive action caused by bentonite clay particles. The drilling fluid with 1 wt.% bentonite clay and 3 wt.% filtrate reducers was the optimized selection for improving the anti-wear performances of WC-10Co4Cr coatings. This work provides theoretical support for understanding the tribological behaviors of WC-10Co4Cr coatings dprepared by HVOF in the different water-based drilling fluids.