| 摘要 |
PROBLEM TO BE SOLVED: To provide a pipe member for solar heat collection pipe of which coefficient of thermal expansion is about less than half of that of aluminum even if it has a superior coefficient of thermal conductivity.SOLUTION: A pipe member 11 for solar heat collection pipe flows heat medium in it. The pipe member 11 for solar heat collection pipe is manufactured by a centrifugal casting process and formed into a cylindrical shape by metal group composite material in which aluminum or aluminum alloy is applied as base material 12, ceramic particles 13 having a higher specific gravity than that of aluminum or aluminum alloy acting as the base material 12, a higher coefficient of thermal conductivity than that of stainless steel and a lower coefficient of thermal expansion than that of the base material 12 are dispersed into the base material 12 as reinforcing material. The metal group composite material contains ceramic particles 13 by 54 to 70 vol.% when the metal group composite material is 100 vol.%. The ceramic particles 13 are mixed with different several kinds of material with particle diameter of micron order and an average particle diameter Dmore than one digit.SELECTED DRAWING: Figure 1 |
