2022 Volume 61 Issue 1 Pages 264-267
Oxygen–free copper is widely used in ultra–high vacuum equipment and heat sinks because of its high thermal and electrical conductivity and low gas release in vacuum. On the other hand, due to the low mechanical strength of oxygen–free copper, copper alloys such as chromium copper alloys are attracting attention. However, although joining methods have been established for pure copper and oxygen–free copper, chromium copper alloys are difficult to weld because of their poor weldability and large thermal conductivity. In this study, solid phase bonding was attempted by heating and pressurizing the base metal of chromium copper alloy without melting. As a joining method for chromium copper alloys, we used sodium hydroxide and formic acid to reduce and remove the oxide film on the joining surface, with the aim of producing joints with higher joining strength.
