Temperature effect on the Fracture of Laser Welds of Aviation Aluminum Alloys
E. V. Karpov1, A. G. Malikov2, A. M. Orishich2, B. D. Annin1
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:276:"1Lavrent’ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
2Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia";}
Keywords: лазерная сварка, алюминиево-литиевый сплав, прочность, пластичность, влияние температуры, laser welding, aluminum-lithium alloy, strength, plasticity, temperature effect
Abstract
This paper describes an experimental study of the effect of temperature on the fracture of laser welds of Mg- and Cu-containing aviation aluminum alloys. The fracture of alloys and their welds under a uniaxial loading at temperatures of -60, 20, and 85 oC is investigated. It is revealed that the strength and ultimate strain of welds of Cu-containing alloys decrease as temperature rises because of the formation of immobile hot spots of localized plastic shifts. Heating and cooling suppress the Portevin- Le Chatelier effect and significantly reduce the ultimate strain of a Mg-containing alloy, even though such reduction is not observed in a weld. It is shown that, at a negative temperature, the maximum limiting lengthening of the weld of a Mg-containing alloy is achieved, while the formation of secondary cracks is activated during heating.
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