Study On Die Design And Numerical Simulation Of Pure Copper Equal Channel Angular Pressing

Many properties of metallic materials,such as mechanical,physical and chemical properties,are affected by grain size.Grain refinement can greatly improve the properties of the material,but due to the technical level and processing technology constraints,people can only refine the grain to micron size for a long time,and the strengthening effect is not satisfactory.Equal Channel Angular Pressing(ECAP)technology is an important method for preparing ultrafine grained materials by means of severe plastic deformation of approximate pure shear to refine the grain size of metal materials to nanometer scale.At present,many pure metals and alloys have been tested by ECAP technology,which has important research value.In this paper,the ECAP deformation of T2 is explored,but due to the large deformation force is needed in ECAP extrusion,and the deformation resistance of copper is relatively large,the requirement of equipment is always high.In order to reduce the demand for test equipment and ensure that the test can be carried out continuously,a new extrusion die is designed by calculation.In order to analyze the advantages and disadvantages of this set of dies,different angles are carried out by using Deform-3D software.The stress,strain and extrusion force of die with different shapes during extrusion are compared.The simulation results show that the deformation force of circular section specimen is the smallest when the internal angle of the die is 120°.The strain uniformity is also relatively good.In order to verify the validity of the numerical simulation results,the design and manufacture of the round cross section with 120° inner angle of the die was carried out in this paper.The ECAP extrusion test was carried out on the circular specimen,and the properties of the finished specimen were tested.The test results show that the die can be extruded by ECAP on the 630 kN press with a diameter of 12 mm circular section,and the hardness and strength of the samples after ECAP extrusion have been obviously improved.The degree of improvement is positively correlated with the strain of simulation results.