Microstructure and Texture Formation during Hot Rolling of Niobium‐Rich γ TiAl Alloys with Different Carbon Contents

Abstract

AbstractThree γ‐TiAl alloys with a base composition of Ti‐45Al‐7.5Nb (at. %) and different carbon contents were used for hot rolling experiments. The alloys were powder metallurgically produced and subsequently hot‐isostatically pressed. Two hot rolling series with different degrees of reduction during the rolling steps have been performed at temperatures in the upper range of the (α + γ) phase field. Samples for texture analysis and metallography were taken from various stages of the rolling process as well as after additional annealing. Light‐optical and scanning electron microscopy images clearly show the influence of the different carbon contents on the recrystallization behaviour. The rolling texture of the γ‐TiAl phase is dominated by texture components, which indicate mechanical twinning as a predominant deformation mechanism. The hot rolling texture of the α‐Ti(Al) phase exhibits components similar to those known from titanium based alloys as well as components probably resulting from co‐deformation with the γ‐TiAl phase.