Both PCD(Polycrystalline diamond) and Tungsten Carbide are widely used in diamond tools. PCD is more used on concrete grinding discs, to remove epoxy, glue, paint and other floor coatings. Tungsten Carbide is more used on bush hammers, but it also sometimes be used on concrete grinding discs, like the case of our HTC grinding disc SYF-P25.
PCD is a matrix of diamond grains that are grown together using proprietary diamond presses (formed in a large High Temperature-High Pressure (HT-HP) press). The upper dark layer is the PCD and the substrate is Tungsten Carbide. So, after the layer of PCD has been exhausted, The Tungsten Carbide exposed and continued to work.
Actually, in diamond tools industry, tungsten carbide is famous for the material of bush hammer, which is used to get different kinds of finishings on stones and concrete(like litchi surface, equidistant lines). It has lots of different grades, such as YG6, YG8, YG10, and etc, for different uses. The common shape of Tungsten Carbide are point, triangle, knurling and star.