Abstract: Embodiments relate to the field of superhard materials, and to a polycrystalline diamond compact (PDC) and a preparation method therefor, and a cemented carbide substrate. The cemented carbide substrate includes a binding phase and a tungsten carbide. The binding phase includes a cobalt and a metal additive. The metal additive is selected from one or more of nickel, chromium, manganese, molybdenum, tin, copper, palladium, silver, aluminum, and platinum. By introducing specific elements and controlling proportions of the elements, the corrosion-resistant binding phase is formed, thereby improving the corrosion resistance of the cemented carbide substrate. Due to that the corrosion-resistant binding phase changes the corrosion mechanism of the cemented carbide substrate, the changed corrosion mechanism is more adapted to the usage scenarios of the PDC, effectively improving the corrosion resistance and erosion resistance of the PDC, and thereby improving the service life of the PDC.

Abstract: A surface-modified polycrystalline diamond and a processing method thereof are provided in the present disclosure. The polycrystalline diamond comprises a polycrystalline diamond body, holes are formed on the polycrystalline diamond body after a catalyst metal is removed, and the holes are embedded with a non-catalyst metal after the catalyst metal is removed therefrom. Thus, thermal damage and stress damage to the polycrystalline diamond during operations at a high temperature are eliminated, improving the thermal conductivity of the surface of the polycrystalline diamond, reducing the temperature of the area around the operating point of the polycrystalline diamond and, therefore, the service life of the polycrystalline diamond is prolonged.