銅―モリブデン拡散接合部に及ぼす銅中の酸素の影響

抄録

Diffusion bonding process was carried out to make a joint of copper and molybdenum at 700 to 900°C, and the effect of oxygen content in copper and post heating treatment on the tensile strength of the joint was investigated. Additionally, the oxide product formed at the bonding interface was observed by SEM and identified by XRD.
It was found that the tensile strength increases with increase in bonding temperature for the joint of molybdenum to oxygen-free high conductivity copper. On the other hand, the tensile strength of the joint of molybdenum to tough pitch copper is low because of the formation of brittle oxide, MoO₂, at the bonding interface.
To clarify the formation of the oxide at the bonding interface, change of the composition at the copper surface were measured using Auger electron spectroscopy. On oxygen-free high conductivity copper, sulfur segregates to the surface at high temperature. While, on tough pitch copper, oxygen increases on the surface at high temperature.