Natural diamond tools are mainly used for Ultra-precision mirror processing of red copper, copper alloy, precious non-ferrous metals such as gold, silver and rhodium, and special parts, such as video camera disk, optical plane mirror, polygon mirror and quadric mirror. But its crystal anisotropy makes the tool expensive.
The performance of PCD depends on the content of diamond grain and cobalt, and the tool life is 10-500 times of that of cemented carbide (WC matrix). It is mainly used for turning various non-ferrous metals such as aluminum, copper, magnesium and their alloys, hard alloys, fiber plasticized materials with strong wear resistance, metal matrix composites, wood and other non-metallic materials. The cutting speed, feed speed and cutting depth during the cutting process depend on the workpiece material and hardness. The performance and application of Artificial Polycrystalline Diamond Composite (PDC) is close to that of PCD tools. It is mainly used for cutting non-ferrous metals, hard alloys, ceramics, non-metallic materials (plastics, hard rubber, carbon rods, wood, cement products, etc.), composite materials, and gradually replaces hard alloy tools.
Because there are some residual bonding metals and graphite between diamond particles, the bonding metals distributed in coalescence or vein shape will reduce the wear resistance and service life of the tool. In addition, there is a residual amount of solvent metal, and the solvent metal is in direct contact with the diamond surface. Reduce the oxidation resistance of PDC and the heat resistance temperature of the tool, so the cutting performance of the tool is not stable. The preparation process of diamond thick film cutting tool is complex because of the high interface energy between diamond and low melting point metals and their alloys.
It is difficult for diamond to be infiltrated by ordinary low melting point solder alloys. The weldability is extremely poor, and it is difficult to make tools with complex geometry. Therefore, TDF welding tools cannot be used in high-speed milling. The reason why diamond coated tools can be used in high-speed machining is that in addition to the excellent mechanical properties of diamond coated tools, diamond coated tools can be used to prepare milling cutters with arbitrary complex shapes for high-speed machining such as aluminum titanium alloy aviation materials and difficult to process non-metallic materials such as graphite electrodes.
