The ceramic mold needs to use high-quality ceramic materials. The silicon nitride ceramic material is chosen here. The ceramic mold made of silicon nitride ceramic material is superior to other metal molds, mainly because the silicon nitride ceramic material has many excellent properties. Performance.
First, the hardness of silicon nitride ceramic materials is as high as HRA93, which is harder than ordinary cemented carbide. The high hardness determines that the ceramic mold made of silicon nitride ceramic material has better wear resistance and longer service life.
Secondly, the silicon nitride ceramic material is chemically stable, corrosion-resistant, and does not react with other inorganic acids except hydrofluoric acid. It does not react with oxygen in a dry atmosphere at 800 ° C. Above 800 ° C, silicon oxide film is formed on the surface. As the temperature increases, the silicon oxide film gradually becomes stable, and a dense silicon oxide film can be formed with oxygen at about 1000 °C. It can be kept stable up to 1400 °C, so there is no need to worry about the ceramic mold being affected by high temperature and chemical substances.
In addition, silicon nitride ceramics are not magnetically permeable, so they do not actively generate energy. Ceramic molds made of silicon nitride ceramic materials also have higher welding stability, so that the later ceramic molds can be more assured when used. ,stable.
Of course, silicon nitride ceramics themselves have certain disadvantages. At present, the most important possibility is that the toughness of the silicon nitride ceramic material is not high enough, so the ceramic mold made of the silicon nitride ceramic material must be careful in use to avoid the occurrence of bumps.