This device is an ideal ignition device for diesel engines. It uses silicon nitride ceramic material as the heating element. Through the shape and size of the heating element, the layout of the heat source, the selection of the heating wire material and the design of the parameters, it adopts the wire winding process, the forming and sintering process of the heating element blank, the grinding process, and the heating The sealing process of the body and the metal sleeve and the sealing process of the upper end of the shell make the product have the characteristics of fast heating speed and long service time. This product is mainly used to improve the cold start performance of internal combustion engines.
In order to prepare a high solid content silicon nitride suspension, the surface modification effects of different dispersants (ammonium citrate, tetramethylammonium hydroxide, ammonium polyacrylate and acrylic acid) on the surface of silicon nitride powder were studied. It was found that ammonium citrate, tetramethylammonium hydroxide, and ammonium polyacrylate could not be adsorbed on the surface of silicon nitride powder to change the surface characteristics of the powder; while the acrylic acid polymerization process caused the polyacrylic acid molecular chain to be adsorbed on silicon nitride. On the surface of the particles, the isoelectric point of silicon nitride powder is reduced from pH≈4.3 to pH≈2.1. Through this surface modification method, the dispersion characteristics of silicon nitride powder in water are improved, and the solid phase volume fraction is prepared. 50% silicon nitride suspension. This surface modification method does not change the chemical composition of the silicon nitride powder, and facilitates the accurate control of the chemical composition and phase composition when preparing silicon nitride-based ceramics.
