Abstract
The aim of this study is to investigate the effect of misorientation angle at bonded boundary on the tensile properties and the interface energy at the bonded boundary. The interface energy was evaluated with an observation of dihedral angle of the groove with a free surface which was achieved by thermal etching. The misorientation angle at the bonded boundary was measured by the electron channelling pattern method. The results obtained are as follows. (1) The interface energy at the bonded boundary depends on the misorientation angle at the bonded boundary, the bonding temperature and the thickness of surface oxide film. But the fracture strength does not depend on the misorientation angle. (2) The interface energy at the low angle bonded boundary below 5° is lower than that at the grain boundary in the base metal. The interface energy at the high angle bonded boundary at 18 up to 30° is higher than that in the base metal. (3) The interface energy of bonded boundary decreases with an increase in bonding temperature and a decrease in thickness of surface oxide film. (4) The number of void at the low angle bonded boundary is fewer than that at the high angle bonded boundary after the thermal etching, the size of the void is smaller than that at the high angle bonded boundary. The number and size decrease with an increase in the bonding temperature.
