Drilling performances and wear characteristics of coated drill bits during drilling reinforced concrete

This paper deals with the investigation on the microstructure and wear behavior of uncoated, Al₂O₃-13 wt% TiO₂, and WC-12 wt% Co-coated drill bits intended for drilling reinforced concrete. Atmospheric plasma spraying technique was employed to fabricate the above coatings on high speed steel drill bits. The circularity measurements of the drilled holes were carried out using MATLAB. The holes drilled using WC-12 wt% Co-coated drill bit showed a better circularity depicting enhanced wear resistance as compared to that of the uncoated and Al₂O₃-13 wt% TiO₂ drill bits. The improvement in the wear resistance of WC-12 wt% Co-coated drill bit is attributed to its higher hardness and lower porosity. Thrust force was observed to be lower for WC-12 wt% Co-coated drill bit depicting less amount of wear. This study suggests that WC-12 wt% Co-coated drill bits can be a potential candidate for drilling reinforced concrete.