Silicon nitride hot pressing sintering

Also known as pressure sintering, hot pressing sintering is the powder loading within the mold, pressure and heat at the same time, after a period of time to make powder sintering forming a dense and uniform products, because of the hot pressing sintering can complete the press and sintering at the same time, so you can quickly get the cold press sintering under low pressure to reach the density.In principle, all powder parts that can be made by common methods are suitable for hot pressing, especially for making dense refractory metals and compounds.

Take silicon nitride as an example. A sintering aid such as magnesium oxide is added to the silicon nitride powder, and densification can be achieved by applying a pressure of 300 kg/cm2 at 1700 °C. In this case, since silicon nitride reacts with the graphite model to form silicon carbide on the surface, a layer of boron nitride is applied to the graphite model to prevent the reaction from occurring and to facilitate demolding. When using this release agent, always pay attention to it under hot pressing conditions.