Simulation And Analysis Of Extrusion Forming Process For Superalloy Blades

Extrusion is one of the necessary steps in leaf blade processing with the advantages of complex shaped workpiece processing capacity, high precision, mechanized and automated production process, and full use of the plastic properties of metal materials. Because of the irregular shape of the blade, various influencing factors in hot extrusion, and difficulties in theoretical solving, research on extrusion lacks systematic understanding. In industrial manufacturing, the most commonly used mehod is making assumptions about the problem, and then using empirical formulas and experimental data to correct processing parameters, whichrequires a lot of experiments, resulting in a waste of time and energy. Therefore, research on the extrusion patterns and factors in the leaf blade processing is of great importance for the processing parameter optimization. This paper establishes a numerical simulation platform in the finite element software DEFORM-3D to do further research about GH4169 alloy blade extrusion.To make the model closer to the actual extrusion processing,study of fracture criterion of GH4169 alloy in the forming process is essential. The mechanical properties experiment and the simulation of GH4169 alloy are combined to obtain the corresponding parameters in fracture criterion formula. The optimum fracture criterion is obtained by mathematical method which can be used in the extrusion simulation process.The rebuild of material constitutive model is necessary because of the sensitivity of GH4169 alloy to deformation rate at high temperature.. Owing to the highly nonlinear boundary conditions, this paper studies the constitutive model and chooses the Kumar model as the best model for blade hot extrusion research. Based on the true stress-strain data obtained by five sets of experiments in hot compression experiments, the parameters of the constitutive model are determined. Then the constitutive equation of the material is added to the software library. The constitutive equation is based on high temperature conditions, and it is suitable for GH4169 alloy at temperatures above 900℃ only.The hot extrusion processing parameters are set after choosing fracture criterion and constitutive model.. Finally, according to the extrusion factors of initial billet temperature, friction coefficient, and extrusion speed, three process schemes are achieved and the effect law of the factors on the forming processing are obtained.Conclusively, theoretical analysis, simulation and experiments are combined to do a comprehensive research on the influencing factors in extrusion processing in this paper. A method for simulation model estabilishment and processing parameter selection are provided for actual production.