Experimental investigation of specific energy and wear intensity of diamond-impregnated core bits in rock drilling

processes. The wear of drill bits is closely related to the specific
energy that expresses the energy consumption of the drilling process
and significantly affects the total cost of drilling. In this article, the
correlation between the wear intensity and the specific energy was
examined. For the purpose of obtaining the necessary information, a
series of experiments were performed on a horizontal laboratory
drilling rig with the use of 8 types of rocks and 5 diamondimpregnated small-diameter core drill bits with synthetic diamonds
of various qualities. The selected drilling mode was the mode with a
constant rotation speed and an increasing thrust force. Results of the
experimental measurements indicated that relatively high rotation
speeds were preferred for the tested drill bits for the purpose of
efficient drilling. The lowest amount of the specific energy required
for drilling was observed for sandstone and andesite, i.e. the rocks in
which radial cracks were formed around the chipped-off crater during
the drilling. A simple linear regression between the intensity of wear
of the drill bits and the specific energy was found. The evaluation of
the results of this experimental research also showed that the quality
of the used diamonds significantly affected the wear intensity.