|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Ultrafine Grained Materials IX
||Effects of Severe Plastic Deformation on the Grain and Precipitate Structures in Beta Ti Alloys
||Ahmad Zafari, Wei Xu, Kenong Xia
|On-Site Speaker (Planned)
The effects of severe plastic deformation (SPD) by high pressure torsion (HPT) on the microstructures of a metastable β Ti-5553 alloy and a stable β Ti-20Mo alloy were investigated. Much finer grains of < 50 nm were achieved in Ti-5553 compared to > 100 nm in Ti-20Mo. The more effective grain refinement was attributed to the formation of the stress induced α" martensitic plates which divided β grains into smaller domains and enabled subgrains to form even in nano-sized grains. Aging at 600 ℃ of the HPT processed alloys resulted in equiaxed α precipitates, compared to the lamellar morphology formed during ageing of the undeformed β alloys. Extensive electron microcopy on the samples aged for various times revealed the steps through which the equiaxed α formed.