Abstract:Thermo-mechanical rock fragmentation drilling technology (TM ) is a kind of new drilling method, which firstly makes use of the friction energy produced by drill bit and rock to heat the rock, and then uses the cutting unit to complete the rock fragmentation. It improves the drilling efficiency and speed, because the physical properties such as intensity, hardness and wear resistance of most kinds of rock are weakened under high temperature and alternating heat stress conditions. The friction unit of TM bit is made of Sialon, of which the wear resistance is 2.8 times as much as that of YG alloy and the cost is only 1/10 times that of YG alloy. In the article, the author expatiates the structures and working principles of TM drill tool and bit in detail. Drilling experiment shows that the friction unit of TM bit can produce enough heat energy to high temperature(>600 ℃), TM drilling technology is feasible, it can improve drilling efficiency and decrease the cost of drilling.