ISSN:
1460-2695
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
In order to characterize the influence of hydrogen on the mechanical properties of β-titanium alloys, monotonic tensile and strain-controlled fatigue tests were performed on samples of the metastable alloy Ti-3Al-8V-6Cr-4Mo-4Zr in uncharged (0.5 at.% hydrogen) and hydrogen-charged (3-4 at.% hydrogen) conditions. The hydrogen was introduced into the material during the last 8 h of an ageing treatment (28 h at 482°C) from the gas phase, whereas the reference (uncharged) specimens were annealed completely in vacuum. The results of the mechanical tests indicate that hydrogen slightly increases the strength of the alloy in monotonic as well as in cyclic loading. Under tensile loading the fracture strain decreases as a result of hydrogen. Under cyclic loading both charged and uncharged conditions show initial softening followed by a saturation state. The cyclic lifetime at a constant total strain amplitude, however, is not reduced by the hydrogen charging. The effect of hydrogen on the mechanical behaviour can be interpreted and understood on the basis of microstructural observations that reveal a hydrogen-induced change in the precipitation state. This indirect influence of hydrogen on the microstructure, which leads to a reduction of the mean size of the α-precipitates, in combination with a slight decrease on the volume fraction of the α-phase, seems to dominate over any direct intrinsic hydrogen effect
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1460-2695.1996.tb00178.x
