A new diamond bit for extra-hard, compact and nonabrasive rock formation

WANG Jia-liang(王佳亮)^{1, 2}, ZHANG Shao-he(张绍和)^{1, 2}

(1. Key Laboratory of Non-ferrous Metal Ore Forecast of Ministry of Education, Changsha 410083, China;
2. School of Geo-sciences and Info-physic, Central South University, Changsha 410083, China)

Abstract:A new impregnated diamond bit was designed to solve the slipping problem when impregnated diamond bit was used for extra-hard, compact, and nonabrasive rock formation. Adding SiC grits into matrix, SiC grits can easily be exfoliated from the surface of the matrix due to weak holding-force with matrix, which made the surface non-smooth. Three Ф36/24 mm laboratorial bits were manufactured to conduct a laboratory drilling test on zirconiacorundum refractory brick. The laboratory drilling test indicates that the abrasive resistance of the bit work layer is proportional to the SiC concentation. The higher the concentration, the weaker the abrasive resistance of matrix. The new impregnated diamond bit was applied to a mining area drilling construction in Jiangxi province, China. Field drilling application indicates that the ROP (rate of penetration) of the new bit is approximately two to three times that of the common bits. Compared with the common bits, the surface of the new bit has typical abrasive wear characteristics, and the metabolic rate of the diamond can be well matched to the wear rate of the matrix.

Key words:SiC grits; impregnated diamond bit; non-smooth surface; diamond; rock fragmentation mechanism