The Paton Welding Journal, 2023, №05



2023 №05 (05)

DOI of Article 10.37434/tpwj2023.05.06

2023 №05 (07)

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The Paton Welding Journal, 2023, #5, 35-41 pages

Fluxless brazing of aluminium alloys by brazing filler metal of Al-Ge system

O.M. Sabadash, S.V. Maksymova

E.O. Paton Electric Welding Institute of the NAS of Ukraine. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

Abstract
The paper gives the results of investigations on fluxless brazing of АD1М, AMts (Al–Mn), AD31 (Al–Mg–Si) aluminium alloys (Al–Mg–Si) with application of Al–25Ge–5Si–5Cu–1.5Mn–0.15Ti brazing filler metal at the temperature of 550 ± 5 °С in the atmosphere of high-purity nitrogen. The results of high-temperature differential thermal analysis were used to determine the solidus and liquidus temperatures of the brazing filler metal. Thermal effects on the derived thermal curve are indicative of the presence of three phases, which correlates with the results of X-ray microprobe analysis. It is shown that the brazing filler metal structure in the initial state is formed by two solid solutions, based on α-Al and β-GeSi and eutectics. Mechanical testing revealed that the short-term strength of the brazed joints is higher than that of the base metal, and fracture occurs in AD1M alloy. Application of steplike cooling of AD31 alloy brazed joint with soaking at the temperature of 500 C promotes increase of shear strength from 84 to 102 MPa. 42 Ref., 1 Tabl., 7 Fig.
Keywords: fluxless brazing, aluminium alloy, germanium brazing filler metal, nitrogen, brazed joint, shear strength heterogeneity

Received: 18.04.2023
Accepted: 29.06.2023

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