Effect of Rapid Heat Treatment on the Microstructure of Alpha+Beta Titanium Alloys

Mujahid, S., Boostani, A. F., Oppedal, A. L., Krivanec, C., Whittington, W. R., Allison, P., Bhattacharyya, J., Agnew, S., & El Kadiri, H. (2018). Effect of Rapid Heat Treatment on the Microstructure of Alpha+Beta Titanium Alloys. MS&T 2018 Proceeding. Columbus, OH: TMS. 5.

Alpha plus beta titanium alloys are widely used in a variety of industries, with Ti-64 (6 wt% Al, 4 wt% V) alloy accounting for over half of the titanium used worldwide1. The enhancement of the material’s mechanical response is an active research topic. Despite the classical notion of strength and ductility being mutually exclusive, more demanding applications have placed an emphasis on the development of an optimized microstructure. A well-designed bimodal microstructure has been shown to strike an excellent balance of strength and ductility 2. Such a microstructure consists of globular, equiaxed primary alpha grains which are surrounded by colonies of alternating alpha and beta lamellae which are formed through the transformation of prior beta grains. The refinement of such a bimodal microstructure can produce a material with significantly higher ductility as compared to the typical lamellar microstructures3. This increased ductility also manifests itself as an improvement in the fatigue and creep performance, as well as a reduction in slip length during deformation, which is crucial to the enhancement of mechanical response under dynamic loading.