TiB2金属陶瓷/TiAl钎焊连接接头应力的数值模拟

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

关键词:  钎焊  TiB₂金属陶瓷  TiAl  数值模拟

Key words:  brazing  TiAl  TiB₂ cermet  FEM

摘要:

利用有限元方法分析了采用Ag基钎料钎焊TiB₂金属陶瓷与TiAl接头在冷却过程中的应力分布情况,并研究了连接温度对接头处应力的影响。结果表明,在钎料与TiB₂金属陶瓷和TiAl的连接界面处均存在一定程度的应力集中,其中钎料与TiB₂金属陶瓷的连接界面应力相对较大。连接温度变化时,应力的分布基本没有变化,只是随着连接温度的降低,应力的数值随之减小。

Abstract:

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.