On the comprehensive performance enhancement of polycrystalline diamond compact by initial diamond particle ratio optimization and cobalt removal treatment

The global oil and gas exploration was towards deep and ultra-deep formations. The complex drilling environment of the deep formations put forward higher requirements on the performance of drill bit materials. As the most commonly used drill bit materials in oil drilling, the performance of polycrystalline diamond compact (PDC) directly affected the drilling efficiency, drilling quality and drilling cost. Extensive researches showed that the diamond particle ratio optimization and cobalt removal treatment could highly improve the performance of PDC cutters. Therefore, in this paper, high performance PDCs with trimodal diamond particle size was prepared and the cobalt binder in polycrystalline diamond table was removed by acid leaching methods. The performance of cobalt-removed trimodal particle size PDC samples was compared with cobalt-removed single particle size PDC to study the influence of particles size on the performance of cobalt removal PDC. The performance test results showed that the abrasion resistance of trimodal diamond particle size PDC was improved by two-fold after the cobalt removal treatment, and compared with single particle size PDC after cobalt removal, it also was improved by 33 %. After diamond particle ratio optimization, the impact toughness of PDCs was also improved by up to 110.5 %.