COPPER PIPE FORMED OF COPPER OR COPPER ALLOY

摘要

PROBLEM TO BE SOLVED: To provide a copper pipe formed of copper or a copper alloy preventing roughness of a heat pipe surface and cracking in machining by restraining crystal grains on the surface from becoming coarse by heating at 800-1000°C in the copper pipe formed of copper or the copper alloy to be used for a heat pipe. SOLUTION: The copper pipe formed of copper or the copper alloy to be used for the heat pipe is characterized in that tensile strength in a pipe axis direction is 240-330 N/mm2, that a yield ratio which is a value obtained by dividing 0.2% yield strength by tensile strength is 0.30-0.99 and that elongation is 5-40%. This copper pipe formed of copper or the copper alloy is also characterized in that an average crystal grain diameter in the pipe axis direction on the outer surface after heated at 1000°C for 60 minutes is less than 0.40 mm and that grooves parallel in the pipe axis direction or a spiral groove is formed on the inner surface of the copper pipe formed of copper or the copper alloy. COPYRIGHT: (C)2009,JPO&INPIT