The Main Processing Method For Diamonds
Let's move on to how diamonds are made.
1. Diamond sintering body cutter
The diamond thick film was processed into diamond grain with an average particle size of 32 to 37 m or directly by high temperature and high pressure to obtain diamond grain, and the grain powder was stacked on WC-16wt %Co alloy, and then used Ta foil to isolate it, sintered at 5.5GPa, 1500 degrees C for 60 minutes, made of diamond sintering body, with this sintering system into a car knife has a high wear resistance.
2. Diamond thick film welding tool
The production process of diamond thick film welding tools generally includes: preparation of large areas of diamond film, cutting diamond film into the shape size required for the tool, welding of diamond thick film and tool base material, grinding and polishing of diamond thick film cutting edge.
(1) Preparation and cutting of diamond thick film
The commonly used method for preparing diamond thick film is DC plasma jet CVD. Diamond film hardness, wear resistance, non-conductivity determines its cutting method is laser cutting (cutting can be done in the air, oxygen and argon environment). Laser cutting can not only cut the diamond thick film into the desired shape and size, but also cut out the back corner of the tool, with narrow seams, high efficiency and other advantages.
(2) Welding of diamond thick film tools
Diamond and the general metal and its alloys have a high interface energy, so that diamond can not be soaked by the general low melting point alloy, weldability is very poor. Mainly by adding strong carbide formation elements to copper and silver alloy solder or by metallicizing the surface of diamond to improve the weldability between diamond and metal.
① Active brazing method
Solder is generally welded in an inert gas or vacuum with a copper-silver alloy containing Ti without a melt. Commonly used brazing components Ag-68.8wt, Cu-26.7wt, Ti-4.5wt, commonly used preparation methods are arc smelting and powder metallurgy. Ti, as an active element, produces TiC as an active element with C reflection during welding, which improves the wetting and bonding strength of diamonds and solders. The heating temperature is generally 850 degrees C, keep warm for 10 minutes, and cool down to reduce internal stress.
② Welding after surface metallization
Metalization of diamond surfaces is the coating of metal on diamond surfaces by surface treatment technology, so that their surfaces have metal or metal-like properties. Generally plated on the surface of diamond Ti, Ti and C reaction to produce TiC, TiC and Ag-Cu alloy brazing material has better wetting and binding strength. Common titanium plating methods are: vacuum physical vapor deposition (PVD, mainly including vacuum evaporation plating, vacuum sputter plating, vacuum ion plating, etc.), chemical vapor plating and powder covering sintering. PVD method single coating volume is low, the temperature of diamond in the coating process is less than 500 degrees C, between the coating and diamond is physical attachment, chemical metallurgy. CVD method Ti and diamond chemical reactions form a strong metallurgical combination, high reaction temperature, damage diamond.
