Compared with large single crystal diamond, polycrystalline diamond (PCD) and polycrystalline diamond composite blade (PDC) as tool materials have the following advantages:

1. The crystal grains are arranged in disorder, isotropic, and have no cleavage planes. Therefore, it is not like large single crystal diamonds in terms of strength, hardness, and wear resistance on different crystal planes. It is also due to the existence of cleavage planes. It is brittle.

2. It has high strength, especially the PDC material has high impact strength due to the support of the cemented carbide matrix. When the impact is large, only small grains will be broken, but not as large as single crystal diamond. Therefore, PCD or PDC tools can be used not only for precision cutting and general semi-precision machining, but also for rough machining and interrupted machining (such as milling, etc.) with a larger cutting amount, which greatly expands the diamond tool material The scope of use.

3. It can prepare large PDC diamond composite cutting tool blanks to meet the needs of large processing tools such as milling cutters.

4. It can be made into a specific shape to suit different processing needs. Due to the large-scale PDC tool and the improvement of processing technology such as electric spark and laser cutting technology, triangle, herringbone and other special-shaped tool blanks can be processed and formed. In order to meet the needs of special cutting tools, it can also be designed into wrapped, sandwich and coiled PDC tool blanks.

5. The performance of the product can be designed or predicted, and the necessary characteristics of the product can be given to suit its specific purpose. For example, choosing fine-grained PDC tool material can improve the quality of the cutting edge of the tool, and coarse-grained PDC tool material can improve the durability of the tool, and so on.

In short, with the development of PCD and PDC diamond composite cutting tool materials, their applications have rapidly expanded to many manufacturing industries, and are widely used in non-ferrous metals (aluminum, aluminum alloy, copper, copper alloy, magnesium alloy, zinc alloy, etc.) , Cemented carbide, ceramics, non-metallic materials (plastics, hard rubber, carbon rods, wood, cement products, etc.), composite materials (fiber reinforced plastics, metal matrix composite materials MMCs, etc.) cutting processing, especially in wood and automobiles The processing industry has become a high-performance alternative to traditional cemented carbide.

PDC and PCD material requirements for cutting tools:

1. The DD self-bonding can be widely formed between the diamond particles, and the residual bond metal and graphite should be as little as possible. The bond metal cannot be distributed in agglomerated state or in the shape of leaf veins to ensure that the tool has high wear resistance and long use. life.

2. The solvent metal residue is small. It is best to act as a solvent during the sintering process, and after the sintering process is completed, fill the gap between the sintered diamond grains in the form of an alloy that does not function as a solvent, or the residual solvent metal after sintering is isolated to avoid solvent metal Direct contact with the diamond surface to improve the oxidation resistance of PCD, so as to ensure that the tool has sufficient heat resistance temperature.

3. The diamond grains are small and uniform, and abnormally grown grains are not allowed to improve the impact toughness of the material.

4. The bonding interface between the PCD layer and the matrix or the welding (intermediary) transition layer has high bonding strength and good thermal conductivity to reduce the temperature of the cutting edge.