About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
|
Symposium
|
Additive Manufacturing: Processing, Microstructure and Material Properties of Titanium-based Materials
|
Presentation Title |
Microstructural Instability in Additively Manufactured Gamma-TiAl Alloy |
Author(s) |
Johnson Jacob, Darren Fraser, Stefan Gulizia |
On-Site Speaker (Planned) |
Johnson Jacob |
Abstract Scope |
In this work Ti–48Al–2Cr–2Nb alloy has been manufactured by the Electron Beam Melting (EBM) process with a desire to homogenise the microstructure and avoid cracking. In the case of EBM, it has unique processing characteristics like high preheating temperature and a complex thermal history - a sequence of temperature cycles with a peak value close to the melting point, decreasing in intensity with every additional layer. Microstructural features including lamellar colony size, lamellar thickness and phases present were characterised and correlated to AM conditions and we have shown how it affected the microstructural evolution. A sequential change in composition and morphology was tracked in various layers during the course of EBM, which was identified as being due to microstructural instability of the primary lamellar structure that formed after rapid solidification during the layer by layer deposition. |