Mn Content And Thermomechanical Treatment On The Influence Of 2519 A Alloy Organization Performance

This paper combines "aluminum alloy Impact Dynamic behavior of the structure and characteristics of micro-down" which is belong to the973Project "efficient utilization of high-performance aluminum and aluminum resources in basic research".The thermal deformation behavior of2519A aluminum alloy was studied by the thermal/mechanical compression simulation experiment, analysing the effect of thermal deformation parameters on flow stress of the alloy during high temperature deformation, and combining with hot compre-ssion stress-strain curves, material constants of high temperature defor-mation of the alloy was obtained, and high temperature deformation flow stress constitutive equations was established. By hardness testing, x-ray diffraction (XRD) analysis, the tensile test,metallographic examination, scanning electron microscopy (SEM), transmission electron microscopy (TEM), method, the content of element Mn and thermomechanical treatment affect2519A aluminum alloy on the microstructure and mechanical properties of the experimental results showed:(1) The peak stress decreases with the increase of deformation temperature and the decrease of strain rate.which can be represented by a Zener-Hollomon parameter in the hyperbolic sine equation, it’s hot deformation activation energy is223.11706kJ/mol. The alloy shows dynamic recovery during the strain rate of0.001s-1～1s-1,and shows partial dynamic recrystallization as the strain rate increase to10s-1.(2) The element Mn proved effect on the age hardening behavior of2519A aluminum alloy when Mn content from0.29%increased to0.45%; Accordingly, the time reaching to the peak is short from9h to6h.(3) When the content of Mn of2519A aluminum alloy is0.29%, after solution heat treatment at525℃for1.5h and ageing heat treatment at195℃for9h, the mechanical properties of alloy at room temperature are: σb=505.1MPa, σ0.2=492MPa,8=11.6%。(4) The observation of TEM showed that after solution treatment at525℃for1.5h, water-cooling,15%pre-deformation, spent9hours at 190℃, the2519A aluminum alloy containing0.29%Mn precipitate a large amount of even and fine θ’ phase in intergranular, precipitation-free zone was narrow and discontinuous.(5)The0.29%Mn alloy for the thermomechanical treatment orthogonal test and three levels of three factors orthogonal table L9(33)shows that he best thermomechanical treatments process of the2519A aluminum alloy containing0.29%Mn are:solution treatment at525℃for1.5h,50%pre-deformation and aging at190℃for6hours, he mechaical properties areσb:=520MPa, σ0.2=495MPa,8=9.0%。(6)After the solution treatment at525℃for1.5h,water-cooling,80%pre-deformation, the2519A aluminum alloy age at215℃, precipitate fined θ’ phase in alloy.