Study on the microstructure and properties of Ti40 titanium alloy by Thermo-hydrogenation treatment

Thermo-hydrogenation treatment is a new technology to adjust the microstructure, mechanical properties and thermal processing of titanium alloy by adding hydrogen to the titanium alloys for its reversible chemical reaction. In this paper, the microstructure evolution and tensile properties at both room and high temperatures of β type Ti40 alloy with hydrogenation and dehydrogenation were studied. The results show that the grain size of Ti40 had little variation, and only resulted in slight lattice distortion. At the same time, its strength remains nearly invariant, but the plasticity reduces largely at room temperature. While fracture analyses show that, with the increase of the content of hydrogen, fracture morphology has the features of ductile-brittle transition. And the thermal plasticity of Ti40 hardly changes through the hydrogen charge and dehydrogenation, unless dehydrogenation up to 0. 5wt% H content, while the corresponding high-temperature strength has no reduction.