The Study On Forming Behavior And Process Parameters Of Cast-rolling7050Aluminum Alloy Sheet

7050aluminum alloy is a kind of ultra-high strength with high temperaturestrength and good comprehensive mechanical properties of structural materials,deformation of aluminum alloy belongs to the Al-Zn-Mg-Cu series. And it has beenwidely used in aero field, transportation and other fields, such as manufactures allkinds of important components, including the frame of the aircraft landing gear, wingbeam, bracket and other bearing components, automobile components with highstrength.Twin-roll casting (TRC) process is a traditional production process of castingliquid metal ingots and hot rolling plate strip with other highly concentratedmulti-channel independent processes in a single continuous casting equipment tocomplete, combines rapid solidification and deformation together. It is a short processand near-net forming technology, which not only increases productivity significantly,saves energy, and reduces production costs, but also improves the quality of sheets.The TRC technology with these superiorities may solve the molding problems ofultra-high strength aluminum alloy sheets, produce sheets with uniform chemicalcomposition, and realizes short process, energy conservation and efficiency.In this paper,7050aluminum alloys were studied by numerical simulation andexperiments. The simulation study on twin-roll casting of7050aluminum alloy wasconducted by using ANSYS. By adjusting the roll gap width and the casting speedto determine the reasonable cast-rolling parameters. The7050aluminum alloy sheetof2~4mm thick was produced by vertical twin-roll casting machine, andmicrostructures and mechanical properties of the cast-rolling aluminum alloy wereinvestigated by means of optical microscope (OM), scanning electron microscopy(SEM), Vickers hardness test and tensile mechanical properties test. Determined toobtain casting process parameters with homogeneous, fine grain sizes and reasonablygood shapes are based on twin-roll castling process parameter of7050aluminumalloy to reduce the number of roll casting alloy micro cracks and the segregationphenomenons.The results show that the ideal products of2mm thick cast-rolling sheet could beobtained by using conditions of casting speed12r/min and roller diameter300mm andthe roll gap width1.8mm and casting temperature963K. Microstructures ofcast-rolling7050alloy sheet are inhomogeneous on the crossing section. From theedge to the center, grain size decreases gradually and microstructures become morehomogeneous, showing a transition from dendrite to equiaxed grains. Microstructuresin the edge or near the surface have a lot of second phase particles while the center isfew. Alloying elements have a certain phenomenon of segregation. When otherprocess parameters remain unchanged, the microstructure of alloy is fine and uniform,mechanical properties and plate shapes are good with the increase of roll casting speed and the roll gap width.