Ingredients computing: Because tungsten powder contains a small amount of oxygen, so in addition to consideration when calculating the carbon tungsten carbide powder required, it must also consider the carbon powder and oxygen required for the reaction.
Mixed materials: tungsten carbide powder quality depends on the degree of uniformity of tungsten powder mixed with carbon black, if uneven mix of materials, tungsten carbide powder and layered sinister phenomenon. Cemented carbide production process, in general, the tungsten powder and carbon black mixed in a ball mill (ball feed ratio of 1:1, ball diameter is 35 ~ 50mm), milling time is 2 ~ 4h, no material was observed with the naked eye stratification that is considered mixed.
Carbonized material: tungsten powder carbonization generally carried in graphite carbon tube furnace, carbonization process in accordance with of tungsten powder particle size and tungsten carbide powder size requirements to select, in general fine tungsten powder carbonization temperature of 1300 ~ 1350 ℃, coarse tungsten carbide powder temperature of 1600 ℃, carbonization time is 1 ~ 2h.
Milling: ball mill in a ball mill. Ball feed ratio of 1:1, ball diameter is 10 ~ 45mm, milling time according to process requirements, and generally is 2h. To prevent the powder from flying, sieved to be in the closed situation, the fine particles tungsten carbide (-200 mesh), tungsten carbide particles through a 250 mesh sieve, the coarse grain tungsten carbide through a 60 mesh sieve. The following table is a tungsten carbide ball milling, sifting process table: