Effect of diamond powder grain size distribution on mechanical and application properties of PDC

Three diamond powders (referred to as P1, P2 and P3) with size parameters for narrowness analysis (SPAN) of 0.5, 0.7 and 1.0 in the range of 10-20 μm with normal distribution characteristics were selected to produce PDC cutters (referred to as S1, S2 and S3) and further processed into PDC bits (referred to as Bit1, Bit2 and Bit3). The grain size distribution of the diamond powders, the microscopic characteristics and mechanical properties of the PDC cutters, and the application performance of the PDC bits were also evaluated. The tests showed that as the SPAN of the diamond powder decreases, the surface area average diameter (d s ) decreases while the volume average diameter (d v ) increases. The microstructural characteristics of PDC correlate more closely with d s . The wear resistance and thermal stability of PDC are correlated with d s , while the impact resistance of PDC is more influenced by d v . In the field test , Bit1 showed significant advantages compared to Bit2 and Bit3, the footage increased by 137% and 184%, the rate of penetration (ROP) increased by and 35% and 50% respectively. • Completed tests and evaluations from diamond powders to PDC cutters to PDC bits. • Various grain size parameters have been used to characterise diamond powders. • Microscopic and macroscopic properties of the samples show different relevance. • PDC bits made from uniform diamond powders perform better in the field.