FEM analysis of thermal/residual stresses in brazing TiB₂ cermet/TiAl joints

Finite element method was used to calculate residual stresses that developed when TiAl was bonding to TiB₂ cermet by Ag-based filler metal during cooling from joining temperature. The stresses distributions of the joint in different joining temperature was studied. The results show that the residual stresses concentration caused by the thermal expansion mismatch between three layerswas observed both in TiAl/filler metal interface and in TiB₂ cermet/filler metal interface. Especially, the maximum value of the residual stresses between TiAl and filler metal are higher than that between TiB₂ cermet and filler metal. Stresses distributions are slightly dependent upon joining temperature. But when the joining temperature became lower, the value of the residual stresses at the same position decreased accordingly.