Industrial application of microwave high-temperature sintering roller kiln on silicon nitride ceramics

一.Characteristics and use of silicon nitride

Silicon nitride, chemical formula---- Si3N4, is a kind of important structural ceramic material. It is a kind of super hard material. As a kind of atomic crystals, it featured with lubrication， wear resistance and oxidation resistance under high temperature.It also can resist cold and heat shock, when heating to over 1000℃in air, and then rapid cooling and rapid heating, it also won't shatter. Because of such kind of excellent characteristic of silicon nitride ceramic ,people often use it to make bearing ,gas turbine blade ,mechanical seal ring, permanent mold and etc. If use silicon nitride ceramic which featured with high temperature resistance and not easy heat transfer to make heating surface of engine, it not only can improve the quality of diesel engine, fuel economy, but also can improve the thermal efficiency.

Among ceramic materials,silicon nitride ceramic is with high strength and high temperature resistance ,the best comprehensive mechanics performance, heat shock resistance, oxidation resistance wear resistance and corrosion resistance, which is regarded as the first material in heat engine parts when choosing ceramic .In mechanical industry,silicon nitride ceramic is used for bearing ball, roller, ball seat, mould, new ceramic cutting tool ,pump plunger, heart shaft seal material, etc.

二.Advantage of using microwave high temperature sintering technology to produce silicon nitride

1.Can put the product which using silicon powder or silicon powder and silicon nitride powder mixture according to general ceramic production molding methods under nitrogen atmosphere to nitriding sinter in microwave equipment all at once, until all into silicon nitride.

2. Based on the design concept of microwave heating and microwave high temperature equipment, which can make the product by sintering with high density and good performance.  

3. Energy and power saving, can save energy more than 40% than conventional electric kiln.

4. Covering area and cost of investment of equipment are smaller than those of hot pressing sintering way.

5.Can sinter different types of silicon nitride products batch by batch, which can improve the flexibility

三.Picture of top-hat kiln which can produce silicon nitride products

RWZ microwave high temperature top-hat kiln