INCREASING THE EFFICIENCY OF DRILLING BIT USE IN HARD ROCKS BY HIGH-QUALITY PERFORMANCE OF A DIAMOND-CARRYING MATRIX

Abstract

The work is devoted to the study of the effect of powdered WC monocarbide of different grain sizes, introduced into the composition of the binder of diamond grains of the composition 94 WC + 6Co + Cu in the manufacture of a diamond-bearing matrix of BS�NQ drill bits with a diameter of 75.6 mm, designed by ISM (Ukraine). The effectiveness of the mentioned crowns was evaluated according to the proposed indicator F= ( - mechanical drilling speed; h � the value of the deepening per single experience, � � linear wear of the matrix in height). Experimental drilling on granite blocks showed that with an increase in grain size from 80/63 to 200/600, the efficiency index increased by 1.9 times, and an increase in the percentage of monocarbide from 6% to 12% increased the F value by 10-12%. A further increase in grain size up to 250/200 caused a sharp decrease in the mentioned F index. It has been theoretically and experimentally shown that the use of a "comb" profile of the working end of the matrix in the design significantly (by 2 times) increases the rate of destruction of the face in comparison with a rectangular end. To further increase the efficiency of working on the destruction of the face, it is necessary to create diamond crowns, the matrix of which in height consists of several impregnated layers with a comb profile, separated from each other by layers of material of lower hardness (for example, VK-20).