| 2006 №06 (01) | 2006 №06 (03) |
The Paton Welding Journal, 2006, #6, 7-11 pages
Effect of scandium additions on structure-phase state of weld metal in aluminium alloy joints after heat treatment
L.I. Markashova, G.M. Grigorenko, A.V. Lozovskaya, O.S. Kushnaryova, V.E. Fedorchuk
E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.Abstract
Effect of heat treatment (ageing at 350 °C, 1 h) on changes in structure-phase composition of weld metal in 1460 alloy joints produced by argon-arc welding using Sv1201 and Sv1201 + 0.5 % Sc fillers is considered. It is shown that heat treatment leads to a considerable increase in volume fraction of fine phases, differing in morphology and phase composition. In metal containing no scandium, Al-Cu phases differing in copper concentration are formed, while Al-Li phases have a more complex structure due to inclusions of fine Al-Zr and Al-Cu phases. Complex phase precipitates of the lamellar (Al-Cu/Al3Sc) and globular (Al-Li/Al-Zr, Al-Sc) types are formed in Sc-containing metal.
Keywords: welded joints, aluminium alloy, heat treatment, scandium, structure-phase transformations, dislocation density, composite phase precipitates
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