First, the PDC has high hardness and wear resistance (abrasion ratio). The hardness of PDC is as high as about 10 000 HV, which is the most complex material in the world’s artificial substances, and the hardness is much higher than that of cemented carbide and engineering ceramics—excellent wear resistance due to extremely high hardness and isotropy. Generally, the wear resistance of the PDC is reflected by the wear ratio. In the mid-1980s and 1990s, the wear ratio of the PDC was 40,000 to 60,000 (80,000 to 120,000 in foreign countries); from the mid-1990s to the present, the PDC, wear ratio was 80,000 to 300,000 (100,000 to 500,000 abroad).
Secondly, the PDC has thermal stability. The thermal stability of the PDC determines its range of use. The thermal stability of the PDC is heat resistance, which is one of the critical performance indicators to measure the quality of PDC, as well as its strength and wear ratio. Heat-resistant stability refers to the stability of the chemical properties of the polycrystalline layer (the degree of diamond inking), the change of macroscopic mechanical properties and the bonding of the interface of the PCD layer after heating to a specific temperature in an atmospheric environment (in the presence of oxygen)—Effect of firmness. Changes in thermal stability after sintering at 750 °C, the wear ratio of some domestic manufacturers’ products increased by 5% to 20%, and the impact toughness did not change much. The formula and process used are different, and foreign PDC cutters’ wear ratio and impact toughness do not change much before and after sintering.
There are also PDCs with impact toughness. They are widely used in oil and gas drilling operations as a cutting tool. During the drilling process, due to the combined effect of axial force and horizontal cutting force, the friction between the drilling tool and the hole wall, the bending of the drill pipe string, the unevenness of the bottom of the hole, the residual rock powder, and the vibration of the drilling rig, etc. The PDC is subjected to significant impact. The PDC’s impact resistance reflects the PDC’s toughness and bonding strength, which is a comprehensive index and the key to determining its use effect. In the mid-1980s and 1990s, the impact toughness of the PDC was 100-200 J(200-300 J abroad), and from the mid-1990s to the present, the impact toughness was 200-400 J(more than 400 J abroad).
