About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Titanium Technology
|
| Presentation Title |
Hydrogen promoted Ti3Al precipitation in Ti-6Al-4V |
| Author(s) |
Velile Vilane, Johan E. Westraadt, Robert Knutsen |
| On-Site Speaker (Planned) |
Johan E. Westraadt |
| Abstract Scope |
Temporary hydrogen alloying (THA) treatments can be used to refine coarse Ti-6Al-4V microstructures. However, the formation of brittle intermetallic phases such as Ti3Al are detrimental to the mechanical properties of the alloy. This study focuses on the effect of hydrogen alloying by comparing martensite decomposition in hydrogenated and control samples. The microstructural evolution was characterized using XRD, SEM-EBSD/TKD and HR(S)TEM-EDS performed on the hydrogenated, tempered, and dehydrogenated Ti-6Al-4V samples. The analyses show that hydrogen saturated plate martensite decomposes to form a nano-banded structure which consists of nanosized, periodical Al-rich, and V-rich HCP regions that stabilize into D019 Ti3Al within 3 hours of tempering. In comparison, typical martensite decomposition is observed in the control experiment. The formation of the nano-banded elemental enrichment structure suggests that hydrogen altered the transformation pathway in hydrogenated martensite during tempering leading to Ti3Al formation in the dehydrogenated state. |