Abstract
The work is devoted to increasing the service life of PDC bits when drilling rocks alternating in hardness by equipping tools with additional superhard elements. Experimental data have shown (ISM NAS (Ukraine)) that superhard elements have the following composition: diamond, tungsten carbide, cobalt, chromium diboride and zirconium dioxide, and the latter two components are included in the composite in a ratio of 2:4. Inserts made of a new composite have minimal cracking, increased wear resistance and cutting ability. In the manufacture of new PDC bits, the bottom-hole part of the blades should be equipped with working elements consisting of a PDC cutter and an insert made of superhard composite. It is shown that when the working edges of the PDC cutter and the end of the undercut insert are placed in the same plane, the efficiency of downhole deepening is ensured. To preserve the diameter of the well, the side surface of the blades is also equipped with calibration inserts made of a new composite. The theoretical dependence of the tool feed rate is obtained depending on the number of calibration inserts in the tier, the rotation frequency of the column and the diameter of the inserts.