The use of hard alloy cutting tools embedded and welded on the drill bit body is a tool for breaking rocks, and this drilling method is what we call hard alloy drilling. Hard alloy is the preferred tool material in coalfield geological exploration. Hard alloy drilling accounts for about 80% of the total engineering volume in coalfield geological drilling in China. What issues should be noted during the drilling process? What are the requirements for cemented carbide in coalfield geological exploration?

Firstly, it is necessary to understand the properties of the rock layers and scientifically and reasonably select the type of drill bit

Hard alloy drill bits are suitable for drilling in soft and medium hard rock formations, and are not suitable for drilling in hard rock formations above grade 8. During the drilling process, it is necessary to scientifically and reasonably select efficient drill bits and optimal drilling procedures based on the rock properties.

When drilling into the first type of soft rock, cemented carbide is prone to rock fragmentation, has low rock abrasiveness, and has high drilling efficiency. However, the rock powder generated in the hole is relatively large, and the rock powder particles are also relatively large, which can cause the hole wall to collapse easily.

Hard alloys have a certain degree of abrasiveness when drilling into the second type of rock, and the key problems to be solved during drilling are roughly the same as those in the first type. Therefore, when drilling into mudstone rocks, it is necessary to choose rib type drill bits with a deep cutting depth or a sharp cutting edge.

When drilling hard alloy into the third type of rock, the drilling efficiency is relatively low. Choose various stepped crushing drill bits or various small cutting tool drill bits.

When drilling hard alloy into the fourth type of rock, the characteristics are that the rock is hard, has high abrasiveness, and the alloy wear is inevitably severe, resulting in lower drilling efficiency. The key problem to be solved during drilling is to improve drilling efficiency while extending the life of the drill bit. If the rock is uneven, attention should also be paid to the problem of alloy chipping.