Interface characteristics of Ti6Al4V-TiAl metal-intermetallic laminate (MIL) composites prepared by a novel hot-pack rolling

Journal Article · Mon Oct 15 00:00:00 EDT 2018 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2018.07.010· OSTI ID:22805786

Sun, Wei ^[1]; Yang, Fei ^[2]; Kong, Fantao ^[1]; Wang, Xiaopeng ^[3]; Chen, Yuyong ^[1]

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1. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)
2. Waikato Centre for Advanced Materials, School of Engineering, The University of Waikato, Hamilton 3240 (New Zealand)
3. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

Highlights: • The Ti6Al4V/high Nb-TiAl metal-intermetallic (MIL) composite was fabricated. • The formation of γ and α{sub 2} phase at interface is diffusion controlled. • The formation of O phase at interface is due to the segregation of Nb atoms. • The Vickers hardness from Ti6Al4V to TiAl alloy shows a trend of a decrease then an increase and finally a decrease. - Abstract: Ti6Al4V (wt%)/Ti-44Al-8Nb-0.2W-0.2B-0.03Y (at.%) (high Nb-TiAl) metal–intermetallic laminate (MIL) composite with a defect-free interface was successfully prepared by hot-pack rolling and the interface microstructure was characterized by XRD, SEM, EBSD, and TEM techniques. The results showed that the interface was about 260 μm thick and consisted of four different microstructure regions. The thickness of each region was about 60–80 μm and the microstructure of the four regions consisted of acicular O, α{sub 2}, and β/B2 phases; acicular α{sub 2} phase; acicular α{sub 2} and β/B2 phases; and acicular γ, α{sub 2}, and β/B2 phases respectively. The resulting microstructure of the interface region was attributed to the interdiffusion of Ti atoms from the starting Ti6Al4V alloy layer to the high Nb-TiAl alloy layer and Al and Nb atoms from the high Nb-TiAl alloy layer to the Ti6Al4V alloy layer. The formation of acicular α{sub 2} and γ phases was diffusion-controlled and the Nb segregation at the interface caused the formation of O phase which had specific relationships with α{sub 2} and β/B2 phases. The detailed interface microstructural evolution of the Ti6Al4V/high Nb-TiAl MIL composite and the Vickers hardness of the composite are also discussed in this paper.

• OSTI ID: 22805786
• Journal Information: Materials Characterization, Vol. 144; Other Information: Copyright (c) 2017 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 COMPOUNDS
BACKSCATTERING
BINARY ALLOY SYSTEMS
COMPOSITE MATERIALS
DIFFUSION
ELECTRON DIFFRACTION
INTERMETALLIC COMPOUNDS
LAYERS
MICROSTRUCTURE
ROLLING
SCANNING ELECTRON MICROSCOPY
SEGREGATION
TERNARY ALLOY SYSTEMS
THICKNESS
TITANIUM COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
VANADIUM COMPOUNDS
VICKERS HARDNESS
X-RAY DIFFRACTION