In this article, we’ll try clarifying and shedding more light on a dilemma confronted by many end users of cutting tools to machine composite materials, when they are required to decide which type of tool to use for their application. There are mainly two types of diamond cutting tools for composites: PCD tools, where the cutting edge is built from a PCD segment of a specific size and shape and CVD diamond coated tools, where the tool’s edge is completely built in a grinding operation and later coated with CVD diamond.

PCD

PCD (Poly – Crystalline – Diamond) is, unlike single crystalline diamond, produced synthetically by sintering together many (Poly) diamond particles, usually in the size of 2 to 30 microns of a meter, with a metal binder (usually Cobalt) at high temperature and high pressure. The rate is 90-95% diamond particles and the rest is Cobalt.

CVD Diamond

(Chemical Vapor Deposition) is a process of coating Nano diamond particles on a Tungsten carbide substrate applying a layer thickness of 6 to 16 microns of a meter. The tungsten carbide substrate has to contain low cobalt content, such as 6% an d has to go through specific surface treatment. The treatment reduces cobalt content in the outer layer, exposing the diamond edges, in order to create sufficient adhesion between the diamond coating and substrate.