The Paton Welding Journal, 2024, №09



2024 №09 (01)

2024 №09 (03)

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цThe Paton Welding Journal, 2024, #9, 12-19 pages

Phase and structural transformations during heating of multilayer Ti/Cu foils of eutectic composition obtained by the EBPVD method

S.O. Demchenkov, T.V. Melnychenko, A.I. Ustinov, O.E. Rudenko, O.V. Samofalov

E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: s_demchenkov@ukr.net

Abstract
Phase and structural transformations in multilayer Ti/Cu foils of eutectic Composition I (Ti50‒Cu50 wt.%) and Composition II (Ti22‒Cu78 wt.%), obtained by layer-by-layer electron beam physical vapor deposition of components in vacuum, were investigated using differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) methods. It was found that during heating of the multilayer foils in the temperature range of 400‒600 °C, due to the diffusion interaction between Ti and Cu layers, the following intermetallic compounds are formed: Cu4Ti, Cu4Ti3, CuTi, and CuTi2 in Composition I foils, and Cu4Ti and Cu4Ti3 in Composition II foils. Upon further heating, melting of the multilayer foils of both eutectic compositions occurs. The Composition II foils begin to melt at a temperature of 879 °C, close to the equilibrium melting temperature of the eutectic alloy of the same composition (875 °C), while in the case of Composition I foils, the onset of melting occurs at a temperature of 915 °C, which is lower compared to the melting temperature of the eutectic alloy of Composition I (960 °C). Considering that Cu4Ti and Cu4Ti3 metastable phases are formed in multilayer Composition I foils, which are components of the more fusible eutectic of Composition II, the reduction in the melting temperature of the foil may be due to its metastable structure. Such behavior of multilayer Ti/Cu foil of eutectic Composition I may facilitate softening of the temperature conditions required to establish physical contact in the material bonding zone during their reactive brazing.
Keywords: Ti‒Cu alloys, eutectic, electron beam physical vapor deposition, vacuum condensates, multilayer structures, phase transformations, melting

Received: 05.03.2024
Received in revised form: 06.06.2024
Accepted: 25.09.2024

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Suggested Citation

S.O. Demchenkov, T.V. Melnychenko, A.I. Ustinov, O.E. Rudenko, O.V. Samofalov (2024) Phase and structural transformations during heating of multilayer Ti/Cu foils of eutectic composition obtained by the EBPVD method. The Paton Welding J., 09, 12-19.

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