Tribotechnical analysis of tungsten carbide additives in mining drilling practice

Abstract

In oil and gas extraction, especially in complex geological conditions, effective and reliable drilling is extremely important. This study presents a comprehensive failure analysis of tungsten carbide-cobalt (WC-Co) tool inserts used in rock drilling operations. The examination included visual inspection, optical microscopy, FESEM imaging, EDS, WDXRF, XRD, and microhardness tests. The results show that abrasive wear and material adhesion are the main failure mechanisms, with wear localized on the edges of the tool due to the influence of high stress and heat. Elemental analysis revealed transferred materials such as Fe, Ca, and Si on the worn surfaces, indicating tool-rock interaction during service. The high average hardness of WC inserts was 1350 Hv, which is suitable for their application. Despite excellent intrinsic properties, the study shows that in-service degradation limits the tool's lifespan. Recommendations include optimizing microstructure, suitable lubricating materials, binder composition, and surface design to improve performance in abrasive drilling environments.