TiAl/RGO (reduced graphene oxide) bulk composites with refined microstructure and enhanced nanohardness fabricated by selective laser melting (SLM)
- State key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)
Highlights: • The average grain size generally refines with increasing the laser scan line spacing. • The phase transformation mechanism during SLM is determined by HRTEM. • Some RGO sheets transform into amorphous carbon during SLM process. • The nanohardness is much higher than those casting counterparts. - Abstract: This work for the first time investigated the effect of laser scan line spacing on the microstructure, phase evolution and nanohardness of Ti-48Al-2Cr-2Nb/RGO (reduced graphene oxide) metal matrix composites (MMCs) fabricated by selective laser melting (SLM). The results show that with increasing the laser scan line spacing from 80 to 140 μm, the average grain size generally decreases from 10.13 to 8.12 μm. The SLM-processed Ti-48Al-2Cr-2Nb/RGO parts are dominated by high-angle (>15°) grain boundaries (HAGBs) and α{sub 2} (Ti{sub 3}Al) phase. With the increase in laser scan line spacing, the contents of HAGBs and α{sub 2} phase both decrease. Due to instantaneous high temperature during the SLM process, some RGO sheets transform to amorphous carbon. The nanohardness of SLM-processed Ti-48Al-2Cr-2Nb/RGO parts increase from 8.13 ± 0.39 GPa to 9.85 ± 0.46 GPa when increasing the laser scan line spacing from 80 to 140 μm, which is much higher than that of the traditional casting TiAl counterparts (4.98 ± 0.10 GPa).
- OSTI ID:
- 22805768
- Journal Information:
- Materials Characterization, Vol. 143; 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
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
ALLOY SYSTEMS
ALUMINIUM COMPOUNDS
AUGMENTATION
CHROMIUM COMPOUNDS
GRAPHENE
LASER RADIATION
MELTING
NANOCOMPOSITES
NIOBIUM COMPOUNDS
OXIDES
PRESSURE RANGE GIGA PA
TITANIUM COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY