Improved Analytical Model for the Calculation of Forging Forces During Compression of Bimetallic Axial Assemblies

Cold forging applied to forming of bimetallic components is becoming more and more popular as a potential one-step manufacturing process. This paper describes the development of improved analytical models to calculate the forming load in bimetallic ring-cylinder assemblies. Using the approach of previous simplified models based on the Coulomb friction model, two new analytical models have been developed considering the shear friction model for a better simulation and approximation to the real problem. The analytical models were validated by experimental results. The forming process was then simulated using the finite element method and a number of cases were analyzed; the new models show better results compared to the original ones, and more specifically the model that considers the resulting force as the sum of forces required to form a cylinder and a ring separately. We propose these new models to solve inherent problems associated with previous approaches due to the friction model implementation.