Ceramic compound tube
　
Designed by exports in new material field of 863 Program, the ceramic compound tube made by our company is the world leading compound tube. Three layers from inside to outside, they are ceramic layer, transition layer and steel layer. The ceramic layer is dense corundum ceramic made in the above 2200℃ condition. Closely integrated with transition layer and steel layer, this tube has advantages of wear-resisting, corrosion-resisting, high-temperature resisting, high strength, high toughness, high mechanical strike resisting. It is the new material for making of world leading conveying tube.

The ceramic compound tube is made by centrifugal method. That is to put the seamless steel compound tube into the tube mold of centrifugal machine, add mixture of iron oxide red and aluminum powder into the tube, the mixture is called Thermit in chemistry. After the rotation of tube mold reaches a certain speed, ignite the Thermit by sparkle, the ignition brings furious chemical reactions and produces large amount of heat. In the heat insulated condition, the temperature can reach as high as 3860k -3600k, this high temperature can melt material in the compound tube include corundum (with melting point 2045℃). The reaction is very short, only lasts several seconds, the melted reactants delaminate according to weight difference. Specific gravity of iron (7．85g／cm3) is twice as much as corundum (3．95g／cm3), so the iron is sent to the inner shell with corundum next to it. Heat is quickly transferred and absorbed, the corundum and iron reaches their freezing points and solidified separately. There are three layers from inside to outside; they are corundum ceramic layer, iron transition layer and steel layer. Between the three layers, there are special metal compounds which links layers firmly with combined pressure strength ≥15MPa and collapsing strength ≥350MPa.