There are differences in the rock-breaking ability of drilling teeth in various types of formations, which is also the reason for the low rate of penetration (ROP) of some drilling tools. Studying the rock-breaking characteristics and energy conversion law of rocks impacted by different polycrystalline diamond compact (PDC) irregular teeth is of great significance to improving the compatibility of drill teeth-rock in percussive drilling. In this study, the dynamic rock-breaking test on rocks with different physical and mechanical properties (granite, grey sandstone, red sandstone) were conducted using the SHPB system installed with PDC irregular teeth (triple-rigid and axe teeth). The approximate range of strain rate during impact is 50 s-1 to 150 s-1. On this basis, the drillability value and dynamic compressive strength of different rocks are calculated, the impact volume of rock after penetration is analyzed, the energy transfer efficiency eta and rock-breaking specific energy delta of rocks impacted by PDC irregular teeth are discussed, and the drill tooth-rock compatibility under impact load is revealed. The results show that the size of the impact crater is closely related to the impact velocity and compression strength of the rock. With the increase of impact velocity and rock strength (the strength of granite is the highest, grey sandstone is the second, and red sandstone is the lowest), the volume of impact crater increases gradually. Furthermore, the shapes of impact craters produced by different teeth also vary, depending on the tooth shape. With the continuous rise of impact velocity, the penetration depth l, damage area S, and damage volume V of impact craters produced by different teeth all increase continuously. Meanwhile, the penetration depth, damage area, and volume of craters produced by triple-rigid teeth are about 2, 1.5, and 3.5 times those of the axe tooth. The axe tooth exhibits higher energy transfer efficiency and rock-breaking specific energy than the triple-rigid tooth during the impact loading. In terms of drilling bit optimization, axe teeth are more suitable for hard formations when triple-rigid teeth are better for soft formations. The findings were expected to form the basis for the selection of drilling teeth type and the optimization of drilling tool engineering parameters in the percussive drilling process.
