Texture formation of α2-Ti3Al during hot forming of γ-TiAl based alloys

In the present study the α2 and the γ texture in a Ti-45Al (at.%) alloy were analyzed by means of x-ray diffraction after hot deformation. The initial Ti-45Al powder compact exhibits a random texture and shows a relatively high amount of α2 phase (about 34 vol.%). Various hot compression tests were performed at temperatures ranging from 700 °C to 1100 °C with strain rates of 5·10-4 s -1 and 5·10-2 s-1 up to a true deformation of ε = -1. Depending on the deformation temperature the γ-TiAl deformation texture consists of pure deformation components (700 °C) or components completely related to dynamic recrystallization (1100 °C). In contrast to the γ phase the α2 phase shows no remarkable changing of the deformation texture with increasing temperature. The α2 deformation texture basically consists of a similar component as it is known from hexagonal α-Ti, namely a tilted basal fiber. However, a significant influence of the deformation rate on the α2 texture formation is observed at temperatures above 800 °C With increasing deformation temperature the α2 texture strengthens by applying a high deformation rate, whereas it weakens for a low deformation rate. This contrary behavior is attributed to the interaction of the α2 and γ phases during texture formation. © 2011 Materials Research Society.

DDC Class

600: Technik

620: Ingenieurwissenschaften

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Texture formation of α2-Ti3Al during hot forming of γ-TiAl based alloys