Polycrystalline Diamond (PCD) is synthetic diamond. PCD tool provides superior wear resistance in highly abrasive materials.
PCD Carbide insert button bit we call it PDC Button Bit, usually used for DTH Bit, RC Bit, Top Hammer Bit. Those bits are used for stone quarrying, mining and geological exploration.
There is another Polycrystalline Diamond Compact bit which is also called PDC Bit with 3-7 wings for oil and gas industry. But it is not we are talking here.
The PDC bit with PCD carbide has much longer serving lifetime than the tugsten carbide bit, i.e, about 5-7 time longer lifetime. Thus it is getting more and more popular in mining worksite.