Evaluation of microstructural development in electron beam melted Ti-6Al-4V

Journal Article · Thu Mar 15 00:00:00 EDT 2012 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2011.12.008· OSTI ID:22066424

Safdar, A ^[1]; Wei, L -Y ^[1]; Snis, A ^[2]; Lai, Z ^[3]

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1. Division of Materials Science, Malmoe University, SE-205 06 Malmoe (Sweden)
2. Arcam AB, SE 43137, Moelndal (Sweden)
3. Institute of Microtechnology and Nanoscience, Chalmers University of Technology (Sweden)

In the current work an investigation of the microstructures of EBM built Ti-6Al-4V test bars has been performed using OM, SEM, TEM and XRD. It has been found that the prior {beta} phase, that formed during the initial solidification, possesses a column shaped morphology with growing direction parallel to built direction. Typical ({alpha} + {beta}) structures namely Widmanstaetten {alpha} platelets with rod-like {beta} phase formed on the interfaces of the fine {alpha} grains, have been observed in the columnar prior {beta} grains. Grain boundary {alpha} phase was found to be formed around the boundaries of the columnar prior {beta} grains. Different phases present in the parts, especially the BCC {beta} phases have been characterized. The TEM/EDX results indicate very high V composition in the {beta} phase. Results of TEM/SAED and XRD also revealed that a superlattice structure could be present in the {beta} phase. Phase transformation sequence is discussed according to the processing history and the microstructures observed. - Highlights: Black-Right-Pointing-Pointer {alpha} + {beta} and individual {beta} phase is observed and characterized by SEM, TEM and XRD. Black-Right-Pointing-Pointer {beta}-phase is identified as rod-like structure embedded in {alpha} matrix and platelets. Black-Right-Pointing-Pointer Phase transformation sequence is discussed as per thermal history and microstructures.

• OSTI ID: 22066424
• Journal Information: Materials Characterization, Vol. 65, Issue Complete; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
BCC LATTICES
ELECTRON BEAMS
ELECTRON DIFFRACTION
GRAIN BOUNDARIES
INTERFACES
MORPHOLOGY
SCANNING ELECTRON MICROSCOPY
SOLIDIFICATION
SUPERLATTICES
TITANIUM BASE ALLOYS
TRANSMISSION ELECTRON MICROSCOPY
VANADIUM ALLOYS
X-RAY DIFFRACTION