| 摘要 |
PURPOSE:To simplify the process, and to improve the productivity by forming a thin film of Nb on the outside peripheral surfae of an aluminum pipe, and thereafter, providing a Cu coating layer on the outside, smoothing the surface, forming a hollow body whose section is a cross type, and melting aluminum. CONSTITUTION:An aluminum pipe 11 is rotated and an Nb thin film 12 is formed on the surface, and a thin film 13 of Cu is made to adhere tightly to its outside. Subsequently, a Cu coating layer 14 is provided on the thin film 13, a smooth surface 15 is obtained by polishing the surface of the layer 14, and thereafter, the pipe is expanded by applying a hydraulic pressure from the inside of the pipe 11, and a hollow body 16 whose section is a cross shape is obtained. Thereafter, a cavity 17 can be obtained by melting the aluminum of the inside surface. |
