Impregnated diamond core bits are often used in core drilling for geological surveys. A tri-state theory is proposed to describe the three states in drilling processes for a diamond particle or a bit. These states are contacting state, cutting state, and ploughing state. Furthermore, the relations among thrust and other mechanical parameters are also summarized. The optimal value of the specific energy is in the cutting state. Several experiment results verified the proposed model. This mechanism is useful for selecting operation parameters in core drilling using impregnated diamond core bits.
Comparative analysis of core drilling and rotary drilling in volcanic terrane
