The wear and fracture mechanisms of WC-Co hardmetal drillbits during rotary-percussive drilling of reinforced concrete vary greatly depending on a number of factors such as the loading spectrum (thermo-mechanical stresses); workpiece material (type of concrete and reinforcement steel); hardmetal grade (WC-grainsize and Co-content); and drillbit geometry (design and location on the drillbit).
Clear differences in both wear mechanisms and wear intensity are evident, being highly dependent on the factors listed above. Additionally, the extreme conditions acting on the cutting edges during drilling of reinforcement steel (rebar) within the concrete induce significant microstructural and metallurgical changes within the near-surface regions of the drillbit.
In this work, experimental studies supported by Finite Element Modelling (FEM) have documented, analysed and quantified the active wear (and fracture) mechanisms in this complex and challenging application. A wide range of experimental variables have been investigated and modelled, covering the large proportion of real-world cases being presented.