METHOD FOR LINING AL2O3 ON INSIDE SURFACE OF METALLIC PIPE

摘要

PURPOSE:To intensify the grain boundary of an Al2O3 lining layer and prevent the crack and exfoliation of a film without using special equipment so as to increase the adhesive power of said film by preliminarily adding silicon oxide and/or copper oxide into a thermit agent. CONSTITUTION:Fe 5 and Al2O3 6 which are the reaction production are put into a molten state by reaction heat when the thermit agent 2 is packed into a metallic pipe 1 and is ignited by a burner 3, etc., from above. The Al2O3 is cooled and solidified by the pipe 1 to form an Al2O3 film 7 on progression of the reaction so that the inside wall of the pipe 1 is coated with said film. The silicon oxide and/or copper oxide is melted by the heat of the thermit reaction if the silicon oxide and/or copper oxide is preliminarily mixed with the thermit agent 2. The molten silicon or copper fills the grain boundaries of the Al2O3 at the time of solidifying on the inside wall of the pipe 1 and the generation of the crack is prevented. The good lining film which obviates the crack and exfoliation is thus obtd.