Dwell-fatigue life dispersion of a near alpha titanium alloy

Observations of Facet Formation in Near-α Titanium and Comments on the Role of Hydrogen

“…The reduction in the number of cycles to crack initiation resulting from dwell loading is obvious; however, the considerably higher growth rates measured directly from the facet surfaces in the current study suggest that the faceted crack growth stage is equally or even more important. This concept is consistent with the recent work of Toubal et al, [75] who have suggested that specimens with better resistance to crack propagation exhibit longer dwell fatigue lives, although the authors have not identified the particular importance of resistance to faceted growth. Now that the preferred orientation of crack initiating grains and crack propagation grains has been identified, it is possible to discuss the effect of microtexture region size on dwell fatigue life.…”

Strain controlled fatigue testing of the metastable β-titanium alloy Ti–6.8Mo–4.5Fe–1.5Al (Timetal LCB)

“…The Young's modulus is significantly higher for the aged state (113 GPa compared to 75 GPa), which is a consequence of its larger amount of ␣-phase. In literature, values for Young's modulus of 60-90 GPa for ␤ alloys and 115-120 GPa for ␣-titanium alloys can be found [7][8][9][10][11]. By this means, ␣-phase fraction of the actual alloy can be approximated to be very high, whereby deviations due to microstructural textures are of course neglected.…”

Macroregion Size Measurements in Bimodal Titanium Forgings Using Two-Dimensional Autocorrelation Method

“…Unfortunately, the properties in dwell-fatigue of nearalpha alloys vary significantly from one sample to the next. [1,2] A better comprehension of the macrostructures present in the material would enable better engine design and performance.…”