AT AP Coated cemented Carbide Cutting Tools 105×15.20×10.16 Semi Finishing

High Quality Carbide Cutting Tools---105×15.20×10.16

The cemented carbide sintering process can be divided into four basic stages:
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 improved.
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 temperature)
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.