Main processing methods of diamond saw blade

The main processing methods of diamond are as follows: thin film coating tool, thick film diamond welding tool, diamond sintered body tool and single crystal diamond tool.

2.1 Thin-film coated tools

Thin-film coated cutting tools are made of diamond films deposited by chemical vapor deposition (CVD) on rigid and high temperature collective materials.

Chemical vapor deposition method is to activate the gas containing C source in a certain way, so that carbon atoms are deposited in a certain area under very low gas pressure, and the carbon atoms form diamond phase in the process of condensation and deposition. CVD methods used for diamond deposition mainly include: microwave, hot filament, DC arc jet and so on.

The advantage of diamond film is that it can be applied to all kinds of cutting tools with complex geometry, such as blades with chip, end milling cutter, reamer and drill. It can be used to cut many non-metallic materials, with small cutting force, small deformation, stable work, slow wear, and the workpiece is not easy to deformation. It is suitable for the finishing of the workpiece with good material and small tolerance. The main disadvantage is that the adhesion between diamond film and matrix is poor and the diamond film tool does not have the regrinding property.

2.2 Diamond thick film welding tool

The manufacturing process of diamond thick film welding tool generally includes: the preparation of large area diamond film; Cut the diamond film into the shape and size required by the tool; Diamond thick film and tool matrix material welding; Grinding and polishing of cutting edge of diamond thick film tool. (1) Preparation and cutting of diamond thick film

Dc plasma jet CVD method is commonly used to prepare diamond thick film. Diamond is deposited on WC-CO alloy (mirror machining on the surface), and the diamond film falls off automatically during the cooling process of the matrix. Diamond film is hard, wear-resistant and non-conductive, which determines that its cutting method is laser cutting (cutting can be carried out in the environment of air, oxygen and argon). Laser cutting can not only cut the thick diamond film into the required shape and size, but also cut out the back Angle of the tool, which has the advantages of narrow slit and high efficiency.

(2) Diamond thick film tool welding

Diamond has high interfacial energy with general metals and alloys, so that diamond can not be infiltrated by general low melting point alloys, and the weldability is very poor. The weldability between diamond and metal can be improved by adding reinforcing carbide forming elements into copper-silver alloy solder or metallizing diamond surface.

(3) grinding of thick film diamond tools

Diamond thick film tool processing methods include: mechanical grinding, hot metal plate grinding, ion beam, laser beam and plasma etching, etc.

2.3 Diamond sintered body tool

The thick diamond film was processed into diamond grains with an average particle size of 32 ~ 37μm by rolling grinding or directly obtained by high temperature and high pressure method. The diamond grains were piled onto WC-16wt%Co alloy and then isolated by Ta foil. The diamond sintered body was prepared at 5.5GPa and 1500℃ for 60 minutes. The turning tool made with this sintering system has high wear resistance.

2.4 Single crystal diamond tools

The single crystal diamond cutter is usually fixed on the knife head, and the small head is fixed on the turning tool rod with screws or platen. The fixing methods of diamond on the knife head mainly include: mechanical reinforcement method (grind the diamond bottom and pressure surface flat, and fix the diamond on the knife head with pressure plate); Powder metallurgy (the diamond is placed in alloy powder and sintered in vacuum under pressure, so that the diamond is fixed on the knife head); Bonding and brazing (fixation of diamond with inorganic binder or other binder). Due to the great difference in thermal expansion coefficient between diamond and matrix, diamond is easy to loose and fall off.