Silicon nitride ceramic material is an excellent high-temperature engineering material, and the future development direction of Si3N4 is: ⑴ Make full use of the excellent characteristics of Si3N4 itself; ⑵ Develop some new fluxes during Si3N4 powder sintering, research and Control the optimal composition of the existing flux; ⑶ improve the powder making, molding and sintering process; ⑷ develop the compounding of Si3N4 and SiC materials in order to produce more high-performance composite materials. The application of Si3N4 ceramics in automobile engines has created a new situation for the development of new high-temperature structural materials.
Silicon nitride ceramics are [Si3N4] tetrahedral, Si atoms are located in the center of the tetrahedron, NAlN ceramics have high strength and modulus, good thermal shock resistance and corrosion resistance, but the atoms are located at the four vertices of the tetrahedron, and then every three The common dielectric constant of two tetrahedrons is relatively high; the thermal stability and dielectric properties of BN ceramics are best in the form of one N atom, which forms a continuous and rigid structure in three-dimensional space, and is one of the few materials whose decomposition temperature can reach 3000 °C. One of the solid network structures of the compound, and has excellent thermal properties in a wide temperature range and compared to other nitride wave-transparent ceramic materials.

The purpose of the ceramic nozzle is to divert the shielding gas, and the size of the ceramic nozzle is closely related to the shape of the appearance of the weld. The size of the porcelain mouth depends on the width of the weld pool and the width of the molten pool. The larger the width of the molten pool, the larger the protection range required, so the larger the porcelain mouth is required. The metal arc welding wire is fed through the wire wheel, the contact tip conducts electricity, an arc is generated between the base material and the welding wire, the welding wire and the base material are melted, and the arc and molten metal are protected by an inert gas argon for welding. In welding, the larger the nozzle type, the better the corresponding shielding gas, and the higher the welding forming factor. At the same time, the original color of welding can be guaranteed.