Order/Disorder in Electrodeposited Aluminum-Titanium Alloys

Published

July 1, 2003

Author(s)

Gery R. Stafford, T Tsuda, C L. Hussey

Abstract

The composition, morphology, and crystallographic microstructure of Al-Ti alloys electrodeposited from two Different chloroaluminate molten salt electrolytes were examined. Alloys containing up to 28% atomic fraction Ti were electrodeposited at 150 oC from 2:1 AlCl3-NaCl with controlled additions of Ti2+. The apparent limit on alloy composition is proposed to be due to a mechanism by which Al3Ti forms through the reductive decomposition of Ti(AlCl4)3]. The composition of Al-Ti alloys electrodeposited from the AlCl3-EtMeImCl melt at 80 oC is limited by the diffusion of Ti2+ to the electrode surface. Alloys containing up to 18.4% atomic fraction Ti are only obtainable at high ti2+ concentractions in the melt and low current densities. Alloys electrodeposited from the higher temperature melt have an ordered L12 crystal structure while alloys of similar composition but deposited at lower temperature are disordered fcc. The appearance of antiphase boundaries in the ordered alloys suggests that the deposit may be disordered initially and then orderes in the solid state, subsequent to the charge transfer step and adatom incporporation into the lattice, very similar to the disorder-trapping observed in rapidly solidified alloys. The measured domain size in consistent with a mechanism of diffusion-controlled domain growth at the deposition temperatures and times examined.

Citation

Journal of Mining and Metallurgy

Volume

39

Issue

Nos. 1-2

Pub Type

Journals

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Keywords

Aluminum-Titanium, Composition, Electrodeposited, Microstructure

Citation

Stafford, G. , Tsuda, T. and Hussey, C. (2003), Order/Disorder in Electrodeposited Aluminum-Titanium Alloys, Journal of Mining and Metallurgy, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=853243 (Accessed September 17, 2024)