An Efficient Electrolytic Preparation of MAX-Phased Ti-Al-C

Journal Article · Mon Oct 15 00:00:00 EDT 2018 · Metallurgical and Materials Transactions B, Process Metallurgy and Materials Processing Science

DOI:https://doi.org/10.1007/S11663-018-1304-X· OSTI ID:22857870

Fan, Jinhang; Tang, Dingding; Mao, Xuhui; Zhu, Hua; Xiao, Wei; Wang, Dihua ^[1]

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1. Wuhan University, School of Resource and Environmental Science, Hubei International Scientific, Technological Cooperation Base of Sustainable Resource and Energy (China)

Large-scale deployment of MAX-phased Ti-Al-C with intriguing mechanical and physicochemical properties is significantly retarded by its harsh preparation conditions, in which costly precursors, high temperature and non-atmospheric pressure are generally imperative. We herein report an efficient electrolytic preparation of MAX-phased Ti-Al-C by direct electro-reduction of solid TiO{sub 2}-Al{sub 2}O{sub 3}-C in molten CaCl{sub 2} at 1223 K under normal pressure. Homogeneous layered Ti{sub 3}AlC{sub 2} with an oxygen content of 4300 ppm is prepared under a voltage of 3 V between the solid cathode and graphite anode for only 4 hours. The electro-reduction of TiO{sub 2}-Al{sub 2}O{sub 3}-C exhibits a much faster speed compared with the electrolysis employing TiO{sub 2}, TiO{sub 2}-C and TiO{sub 2}-Al{sub 2}O{sub 3} as the precursors. Time-dependent electrolysis indicates that TiC{sub x}O{sub y} is the main intermediate. The generation of refractory and highly conducting TiC{sub x}O{sub y} intermediate enhances the reduction. Density functional theory simulations show a weak affinity towards oxygen of the resulting Ti{sub 3}AlC{sub 2}, which is beneficial to fast and thorough deoxidation. The formation of a layered structure of Ti{sub 3}AlC{sub 2} is attributed to the template effect of the precursory graphite. By simply varying the precursory stoichiometry, layered Ti{sub 2}AlC is also prepared. The present protocol featuring affordable feedstock, low temperature, ambient pressure, high energy efficiency and controllable stoichiometry is promising for large-scale application.

• OSTI ID: 22857870
• Journal Information: Metallurgical and Materials Transactions B, Process Metallurgy and Materials Processing Science, Vol. 49, Issue 5; Other Information: Copyright (c) 2018 The Minerals, Metals & Materials Society and ASM International; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA); ISSN 1073-5615
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AFFINITY
ALUMINIUM OXIDES
AMBIENT TEMPERATURE
ANODES
ATMOSPHERIC PRESSURE
CALCIUM CHLORIDES
CATHODES
DENSITY FUNCTIONAL METHOD
ELECTRIC POTENTIAL
ELECTROLYSIS
ENERGY EFFICIENCY
GRAPHITE
OXYGEN
REDUCTION
REFRACTORIES
STOICHIOMETRY
TEMPERATURE RANGE 0400-1000 K
TIME DEPENDENCE
TITANIUM OXIDES