Tungsten steel sintering process

Tungsten steel sintering process can be divided into four basic stages:
1, removal of burn-forming agents stage,Kekai tungsten carbide rod following changes occurred during this phase sintered body:
Removal of the initial sintering agent as the temperature rises, forming agent gradual decomposition or vaporization, excluded from the sintered body, at the same time, more or less forming agent to increase the sintered carbon, carbon amount will vary forming agent different type, quantity and sintering process is changed.
Powder surface oxides are reduced, at the sintering temperature, the hydrogen reduction of oxides of cobalt and tungsten carbide, if the vacuum forming agent removal and sintering, the carbon-oxygen reaction is not strong. Contact stress between the gradual elimination of the powder particles, bonding metal powder beginning to recovery and recrystallization, surface diffusion began, briquette strength increased.
2, solid-phase sintering stage (800 ℃ - eutectic temperature)
Temperatures occur in the liquid phase under the previous, except to continue the process of what happens on stage, the solid-phase reaction and diffusion intensified, plastic flow enhancement, sintered apparent contraction.
3, liquid phase sintering (eutectic temperature - sintering temperature)
When the liquid phase sintered appear after contraction completed soon, followed by crystallization transition, the formation of the basic organization and structure of the alloy.
4, the cooling stage (sintering temperature - room temperature)
At this stage, the organization and the phase composition of tungsten carbide ball steel with different cooling conditions to produce some of the changes that can take advantage of this feature, tungsten steel heat treated to improve its mechanical properties.