Thanks to their good mechanical properties, especially at high temperature, Ti alloys have been proven to be technically high effective material for a wide variety of aeronautic and aerospace applications. However, the big affinity of these alloys to hydrogen (H) leads to its absorption in a huge quantity (until 10000ppm), which leads to severe issues. Indeed, the hydrogen precipitates in the form of a hydride phase (TiHx) brittle at low temperature, leading to the embrittlement of the material.
In the present work, electrochemical cells and thermal desorption analysis technique (TDA) have been used for respectively the hydrogen charging and quantification. Moreover, tensile tests and mechanical constant load tests were used to determine a critical amount of hydrogen from which the material is considered as brittle. The mechanisms of embrittlement were then investigated.
The importance of the samples preparation before the cathodic charging is highlighted as well as TDA atmosphere during the measurement. Indeed, Ti oxide and TiN layers act as barriers during respectively charging and measurement. Concerning the hydrogen critical value for the fragility of the material, results showed the effect of hydride layer thickness.