电致发热多孔SiC陶瓷绝缘涂层的研究

l2O3 collosol was prepared by Sol－Gel method which it used aluminium isopropoxide as principal raw material and porous SiC ceramic as matrix. The matrix was needed cleared Then matrix was dipped into the sol，this step was done repeatedly. Through this method, the surface and inner wall of pore of ceramic was coated with Al2O3, so the coated ceramic can insulate when there was current .It has been confirmed in experiment that there really was the Al2O3 coating on the pore wall of the ceramic. And the resistivity of the ceramic was obviously increased. So that the risk during the process of electric-heating was decreased. As the result the study on the performance of electric－heating is more significant。