High Quality Carbide Cutting Tools---105×15.20×10.16
The cemented carbide sintering process can be divided into four
1: In the stage of removing the forming agent and pre-sintering,
the sintered body changes as follows:
Removal of the molding agent, with the increase of temperature in
the initial stage of sintering, the molding agent gradually
decomposes or vaporizes, and the sintered body is excluded. The
type, quantity and sintering process are different.
The oxides on the surface of the powder are reduced. At the
sintering temperature, hydrogen can reduce the oxides of cobalt and
tungsten. If the forming agent is removed in vacuum and sintered,
the carbon-oxygen reaction is not strong. The contact stress
between the powder particles is gradually eliminated, the bonding
metal powder begins to recover and recrystallize, the surface
diffusion begins to occur, and the briquetting strength is
2: Solid phase sintering stage (800℃--eutectic temperature)
At the temperature before the appearance of the liquid phase, in
addition to continuing the process of the previous stage, the
solid-phase reaction and diffusion are intensified, the plastic
flow is enhanced, and the sintered body shrinks significantly.
3: Liquid phase sintering stage (eutectic temperature - sintering
When the liquid phase appears in the sintered body, the shrinkage
is completed quickly, followed by crystallographic transformation
to form the basic structure and structure of the alloy.
4: Cooling stage (sintering temperature - room temperature)
At this stage, the structure and phase composition of the alloy
have some changes with different cooling conditions. This feature
can be used to heat the cemented carbide to improve its physical
and mechanical properties.