The hot pressing or cold pressing sintering process of the diamond bit is a typical diffusion brazing process. In the initial stage of the production of diamond cutter heads, the use of low-temperature metal powder melting and diffusion brazing high-temperature metal powder is generally used to further inlay and control the diamond; with the development of technology, there are carbide-forming elements (chromium, titanium, vanadium, molybdenum, etc.) Active pre-alloyed powder, through the reaction of active pre-alloyed powder and diamond to form carbides to achieve diffusion brazing or brazing connection, the formation of carbides is slow, the active element in the pre-alloyed powder and the carbon element in the diamond mutual diffusion and migration The process needs to be kept at a certain temperature for a long time to achieve atomic diffusion and reaction, so the hot-press sintering process is easier to achieve this diffusion.

The brazing of single-layer diamond tools generally uses active brazing filler metal or nickel-based brazing filler metal. Through the formation of elements or alloys from strong carbides, the chemical metallurgical bond between the matrix material and the diamond is realized, and the holding force of the brazing filler metal layer on the diamond is improved. . The single-layer brazing method has a large exposure ratio of diamond and is not easy to fall off, so the single-layer brazing diamond tool has sharp cutting and good chip removal. The orderly arrangement of diamonds not only realizes the reasonable arrangement of the diamond layer on the surface of the tool, and gives full play to the cutting effect of diamonds, but also greatly reduces the amount of diamonds, reduces tool costs, and improves cutting efficiency.

The brazing of the diamond bit has its unique characteristics. First, the bit is a powder metallurgical product, and there are countless capillary holes; secondly, the bit is a sintered product, and there are oxides on the surface and inside of the bit; again, the components of the bit are inexhaustible. Similarly, the requirements for brazing materials and brazing processes vary greatly.

Because the allowable heating temperature of PCD is limited (generally the heat resistance temperature is not higher than 720～780℃), the brazing material mainly uses silver-based solder, and the general-purpose silver-based solder has a lower heat resistance temperature and is resistant to diamond and carbide. The wettability is poor. At present, there are dedicated PDC tool brazing materials, which can meet the requirements of PDC brazing by improving the high-temperature strength and fatigue properties of the brazing filler metal and regulating a reasonable brazing process.