Abstract
Tungsten has been used as one of the target materials of X-ray tube. So far, the tungsten is brazed copper for the cooling structure. But the defects such as void often occur at the brazed area.
In this study, diffusion bonding process was tried to make the joint of tungsten to copper. Especially the effect of oxygen content in the copper was investigated using Auger spectroscopy, X-ray diffraction and EPMA. Copper materials used were tough pitch copper (O content : 0.0266mass%) and oxygen free high conductivity copper (O content : 0.0001mass%).
The tensile strength of the joints of tungsten to copper depends on the oxygen content in the copper. The joints of oxygen free high conductivity copper to tungsten fractured at the base metal. On the other hands, the oxide layer of W18O49 was formed at the interface of joints of tough pitch copper to tungsten. The tensile strength of the joints decreased extremely due to the formation of the oxide.
