Critical Observation and Analysis into Wear Phenomena in WC-10%Co Drill Bits

Wear analysis of the cutting tools has always been an interesting area of research for material scientists. It gives new directions to develop new materials with improved mechanical properties and to modify the existing material for desired applications. WC-Co (tungsten carbide-cobalt) cemented carbide is one of an important tool material which is used extensively for metal machining, rock excavation, coal cutting, oil drilling, etc. For many years, a number of research works were carried out to examine the wear mechanisms in cemented carbide. With regard to mining applications, cemented carbide was tested under rock drilling experiments, in-situ coal cutting operations and laboratory wear testing methods. By the present work, an attempt was made to characterize critical wear mechanisms in WC-10%Co cemented carbide after rock drilling experiments. For the purpose, two different twist drill bits were used for drilling two different rock samples, named, granite and marble. The worn out tool samples were examined under field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The wear mechanisms, such as, Rock cover formation, WC grain removal, WC grain cracking, and Rock penetration were mainly observed.