Research On Composite Criterion And Compound Forming Of 7050/2A14 Aluminum Alloy

With the advantages of low density,high corrosion resistance,excellent electrical and thermal conductivity,aluminum alloys are widely used in aerospace,automotive industry,machinery manufacturing and other fields.In some fields with high material requirements,different parts of the parts are required to have different performance parameters,so the composite materials of heterogeneous aluminum alloys can better meet the service requirements.Therefore,it is of great engineering significance to study the coordination of composite deformation of heterogeneous aluminum alloys and their composite rheological behavior to develop,optimize and quantitatively evaluate the composite forging process of heterogeneous aluminum alloys.This paper takes 7050 aluminum alloy and 2A14 aluminum alloy as the research object.Firstly,the influence of temperature,stress and deformation on bimetallic composite forging is quantitatively studied by conducting composite forging test on Gleeble-3800 thermal simulation test machine,and the critical criteria for achieving interfacial bonding are temperature 450℃～500℃,stress 10MPa～15MPa and deformation 20%.The effect of solid solution process on the interface of composite components was studied,and the matching solid solution process was determined to be470℃/4h,and the thickness of the diffusion layer of interface elements could reach 4μm.Then,the influence of temperature,deformation rate and layer thickness ratio on the coordination of bimetallic deformation during composite forging of sleeve parts was simulated and analyzed by DEFORM software,and the degree of coordination of deformation of sleeve parts was measured by the stress-strain difference between the two sides of the interface,and reasonable process parameters were determined,i.e.,deformation temperature of 450°C,deformation rate of 0.1s^-1 and deformation amount of60%.Finally,the simulation results were verified by Gleeble-3800 thermal simulation tester,and the composite rheological curves of the sleeve parts were obtained under the process conditions of deformation temperature 300℃～500℃,strain rate 0.1s^-1～10s^-1 and deformation amount 60%,and the influence law of the structure of the sleeve parts on the rheological behavior was analyzed,and the 7050/2A14 composite rheological curve was established based on the modified curve.Based on the modified curves,the peak stress prediction model of composite forging of aluminum alloy sleeve parts and the principal structure equation considering strain compensation were established,and the microstructure and element diffusion of the sleeve parts under the optimal composite conditions were observed,and it was found that the composite effect at 45°of the interface was better,and the diffusion of Mg,Zn and other elements occurred to different degrees.