Brazing residual stresses in components of different metallic materials

Brazing residual stresses are a consequence of differences between the thermal expansion coefficients of the brazed partners and the solder. In this study, components of copperr, austenitic steel and a nickel-base alloy brazed on ferritic steel are investigated. Using simplifying assumptions, the resulting stress states are estimated and compared with experimental X-ray stress analyses and curvature measurements. This gives clear evidence of complicated inhomogeneous plastic deformations in the compounds, which occur during cooling down from the brazing temperature. In addition, X-ray residual stress determinations allow a quantitative description to be given of edge effects in the compounds examined.