Study On Hot-Stretching Flow Stress And Solid Boss Plate Forging Ability Of 5052 Aluminum Alloy Sheet

In this paper,5052 aluminum alloy sheet is taken as the research object.The mechanical properties,fracture morphology and the forming technology based on the plate forging process are used to explore the cylindrical parts with solid boss structure.Firstly,in order to obtain the stress-strain curve of 5052 aluminum alloy at different temperature and strain rate,the 2mm aluminum alloy sheet was selected for hot tensile test according to the experimental requirements.The results show that in the hot tensile test,with the strain rate with the increase of the material,the yield strength and tensile strength of the material increase continuously,and the section elongation decreases continuously.With the increase of temperature,the yield strength and tensile strength of the 5052 aluminum alloy decrease continuously,and the section elongation increases remarkably.The stress-strain curve was obtained by thermal tensile test of 5052 aluminum alloy sheet under different conditions.The Arrhenius hyperbolic sinusoidal relationship including Zener-Hollomon parameter was used to describe the hot tensile flow stress behavior of 5052 aluminum alloy.The energy stress equation of the 5052 aluminum alloy sheet is 162.72kJ/mol:?=A(?){sinh[?(?)?]}n(?)exp[-Q(?/RT)]The relationship between the parameter functions of each material and the strain is as follows:The fracture morphology of 5052 aluminum alloy at different strain rates and different temperatures was investigated by means of SEM.The results show that a large number of dimples with small size and shallow depth appear at tensile deformation at low temperature.There is a jagged tear rib around the dimple.The depth and size of the dimple increase with the increase of the tensile deformation temperature.When the strain rate is 0.1s-1,the fracture dimple is deep.The surface tearing edge is extremely uneven.As the strain rate decreases,the dimple size increases becomes smaller,indicating that the sample grows and accumulates a large amount of time before the tensile fracture at high temperature and low strain rate.The larger dimples have better plasticity and their forming ability is greatly improved.This shows that the 5052 aluminum alloy has a certain sensitivity to temperature and strain rate.Based on the DEFROM finite element software platform,the parameters in the hot tensile flow stress model of aluminum alloy are obtained.The software is used to simulate the cylindrical parts with convex structure,and the forming temperature is discussed at different forming temperatures.The friction conditions,the raised geometry and the forming properties under the process parameters,the simulation results show that at different temperatures,as the friction coefficient between the punch and the sheet increases,the raised corner radius and the raised radius increase.The value of the convexity is continuously increased,indicating that the formability of the bulge is improved,and the value of the convexity of the solid boss is maximized at 673 K;the back pressure load and the blanking force are increased to promote The fluidity of the material during the forming process increases as the height of the protrusion increases.Finally,according to the characteristics of the process of plate forging,the corresponding mold was designed,and the YP32-315 proportional control extrusion deep drawing composite forming test machine was used to study the shape of the plate forging.The results show that the simulation results are basically consistent with the experimental results when the plate forging is solid,and the differences of different flow stress models in the composite forming process of the plate forging are verified,which provides a scientific basis for further research.