Quantitative Analysis of Alpha Morphology Changes of Ti-17 Alloy with a Lamellar Starting Microstructure
The microstructural changes of alpha morphology in Ti-17 alloy with an initial lamellar microstructure were examined quantitatively using image analysis software. The alpha morphology changes at different locations (center, edge, 0.5R) of the cakes deformed to different strain level were measured by Feret ratio and related to the imposed strain estimated using finite element analysis. It was found that the modification of alpha morphology depended strongly on the forging strains and the locations in the cakes. The distribution curve of Feret ratio was characterized by a single peak at Feret ratio between 1.5-2.5. These peak values increased with the increase in the height reductions. Increasing forging strains caused the high-Feret-ratio lamellae to decrease but low-Feret-ratio alpha to increase noticeably. The average strains for initiation of globalization were of the order of 0.4 and those for completion were of the order of 1.0, which was lower than conventional α+β titanium alloys.
M.S. Dargusch & S.M. Keay
W. D. Zeng et al., "Quantitative Analysis of Alpha Morphology Changes of Ti-17 Alloy with a Lamellar Starting Microstructure", Materials Science Forum, Vols. 618-619, pp. 113-116, 2009