With alumina ceramics to copper brazement of cylindrical shape, the themal stress analysis was carried out by finite element method. Elastic and plastic behaviour was considered to copper, but only elastic behaviour was considered to alumina. Cooling condition was considered to two cases of convection and uniform cooling.
The result of analysis is shown that maximum tensile longitudinal stress is occurred at perimeter of alumina side interface and maximum compressive radial and tangential stresses are occurred at center of alumina side interface. Because of bending effect, tensile radial and tangential stresses are occurred at near bottom of alumina, far from interface. In case of convection cooling, due to rapid cooling of surfaces, greater tensile radial and tangential stresses are occurred at near bottom of alumina than uniform cooling.
Brazing experiment with same materials and shape of theoretical analysis also was performed. Pure titanium foil was used with filler metal for bonding. In filler metal, greater affinity with oxygen than alumina is required for strong bonding. The result of tensile test is shown that fracture was occured in not interface but alumina side.
