Identification of diffusion parameters in welded joints of titanium and its alloys

Titanium and its alloys may experience a progressive embrittlement leading to catastrophic failure. Such embrittlement is a consequence of hydrogen migration and the accumulation of brittle titanium hydrides in the presence of a sharp alloy composition gradient near a weld fusion line. The governing equations for such migration are presented. The identification problem for parameters responsible for this phenomenon is formulated. The sensitivity equations are given in terms of finite elements to solve the problem of identification. Based on numerical procedures the parameters of welded joints due to hydrogen diffusion are identified.