About this Abstract |
Meeting |
Materials Science & Technology 2020
|
Symposium
|
Additive Manufacturing: Alloy Design to Develop New Feedstock Materials
|
Presentation Title |
Opportunities to Improve the Mechanical Properties of Titanium Alloys Produced by Laser Powder Bed Fusion |
Author(s) |
Marco Simonelli, Graham McCartney, Nesma Aboulkhair, Yau Yau Tse, Adam Clare, Richard Hague |
On-Site Speaker (Planned) |
Marco Simonelli |
Abstract Scope |
This talk presents the opportunities that laser powder-bed fusion (L-PBF) offers for the design and development of novel superior titanium alloys. From a detailed study of the solidification path of Ti-6Al-4V, our exemplar material, strategies to increase strength/ductility and address mechanical anisotropy in Ti alloys are proposed. Firstly, (i) the orientation relationship that links the low and high temperature phases (α and β, respectively) and (ii) the crystallographic defects introduced by L-PBF are utilised for prior-β grain refinement through epitaxial recrystallisation. The recrystallisation is characterised by high-temperature EBSD to inform on the early nucleation and growth of the β phase. The alloy design strategy used to develop a novel quaternary alloy Ti-6Al-4V-Fe with heat treatable metastable microstructure for increase in both strength and ductility is then presented. The merits of the design strategy and future outlooks and informed by high-temperature synchrotron X-ray diffraction, EBSD and TEM studies and mechanical testing. |