A Study of Dislocation: Hydrogen Interaction in Titanium Aluminum Alloys via Internal Friction Measurements

摘要

Hydrogen-dislocation interactions in alpha titanium-aluminum alloys were studied via internal friction measurements in the temperature range 200K to 500K. Employing a series of titanium-aluminum binary alloys (0 %, 1 at. % and 3 at. %Al) these interactions were monitored in terms of observation of a damping peak which centers around 390 K at 10 MHz. The activation energy and attempt frequency of the damping peak in pure titanium were found to be 0.28 eV and 4x10 to the 10th power/sec, respectively. Both room temperature plastic deformation and the presence of hydrogen are required to generate this peak. The relaxation strength of the peak in each of the alloys increases at this peak. The relaxation strength of the peak in each of the alloys increases at low hydrogen levels with the square of hydrogen concentration and reaches a plateau when a critical hydrogen concentration is attained. (Author)