| 摘要 |
PURPOSE:To decrease the porosities of a ceramic layer formed on a composite structural pipe and to improve the strength to the same level as that of a base pipe made of metal in a producing method for said pipe wherein a thermit agent in the base pipe is ignited in a centrifugal force field by adding the SiO2 to the thermit agent. CONSTITUTION:A thermit agent consisting of a mixture of Al and iron oxide is loaded in a base pipe 1 made of metal, and said agent is ignited in the centrifugal force field generated by high speed revolutions, whereby thermit reaction is caused. The molten iron and molten Al2O3 formed by said reaction are separated by gravity, and an intended ceramic layer 4 is coated and formed via a metallic layer 3 on the inside surface of the pipe. Here, powder or particles of SiO2 are further added at 5-15wt% as an additive to the thermit agent. Then SiO2 is melted as well by the heat of reaction and forms alumina-silicate ceramics by melting and mixing with Al2O3, whereby the m.p. and viscosity are decreased, the escaping of bubble from the layer 4 is accelerated and porosities are decreased. |
