Vacuum sintering means that metal, alloy or metal compound powder is sintered into metal products and metal billets at the temperature below the melting point under the condition of vacuum degree of (10 ~ 10-3 Pa). Sintering under vacuum conditions, there is no reaction between metal and gas, no gas adsorption effect, not only the densification effect is good, and can purify and restore function, reduce the sintering temperature, and sintering temperature can be reduced by 100 to 150 DEG C, save energy, improve the sintering furnace life and obtain high quality products.
For some materials, it is necessary to combine particles by heating and atom transfer, while induction sintering technology plays a heating role in this process. The advantages of vacuum induction sintering is to help reduce harmful substances in the atmosphere under vacuum conditions (water vapor, oxygen, nitrogen and other impurities), avoid decarburization, nitriding, carburizing, reduction, oxidation and a series of reaction. Gas pore reduction process, reduce the chemical reaction of gas molecules, while the material in liquid phase before the elimination of the surface oxide film, when combined with each other so as to make the material melting materials with more compact and improve its wear resistance and strength. In addition, vacuum induction sintering has a certain effect on reducing the cost of products.
Because the vacuum environment, the gas content is relatively low, so you can ignore the heat conduction and convection, heat radiation, mainly by way of heating component is transferred to the surface of material, according to the sintering temperature of concrete, the physical and chemical properties of the material, select the appropriate heating assembly is also very important. Compared with the vacuum resistance heating, induction heating with medium frequency power supply can avoid the high temperature insulation of the vacuum furnace with internal resistance heating to some extent.
At present, induction sintering technology is mainly used in the field of iron and steel and metallurgy. In addition, in the special ceramic material, induction sintering enhances the bonding of solid particles, contributes to grain growth, compression voids, and then increases the density, forming dense polycrystalline sintering body. Induction sintering technology is also widely used in the research of new materials.