| 摘要 |
PURPOSE:To obtain a heat pipe excellent in a heat transfer performance at a low cost by using non-oxygen copper as a vessel material and forcibly forming an oxidized film on the surface of a groove formed in the inner wall surface of the vessel by use of chemical or thermal means. CONSTITUTION:A tubular vessel 1 is made up of non-oxygen copper, and an oxidized film is formed on the surface of the groove 8. In a case where pure copper is oxidized with chemical means, the surface of copper is covered with a mixture of Cu2O, CuO and Cu2O3 at a ratio depending on the degree of oxidation. These oxides have each an irregular and slender shape, and the surface area thereof is greatly increased, as compared with the flat surface of pure copper. Further since extremely minute recessions and projections are formed between particles of respective oxides, the capillary tube effect with respect to the working liquid greatly increases and wettability is improved. By subjecting the inner surface of the pipe to a chemical treatment in this manner, it can be recognized that the heat transfer performance of the pipe is improved by the formation of the oxidized film. |
