Numerical modelling of powder metallurgical coatings on ring-shaped parts integrated with ring rolling

Today's demands for flexible and economic production of ring-shaped work pieces coated by functional layers can only be met by new manufacturing techniques. These are suitably based on precise process modelling and high-performance control systems. The process-integrated powder coating by radial axial rolling of rings introduces a new hybrid production technique. It takes advantage of the high temperatures and high forces of the ring rolling process. This is not only to increase the ring's diameter, but also to integrate powder metallurgical multi-functional coatings within the same process. To improve the feasibility assessment of the proposed geometries and material combinations as well as to investigate important quantities such as the stress state in the rolling gaps and the residual porosity of the powder metallurgically produced layer, the versatile application of the finite element method (FEM) is crucial. Therefore, parameterized two-dimensional and three-dimensional finite element (FE) models are created. It will be shown that the implementation of a new control mechanism based on Apollonian mutually orthogonal circles and bipolar coordinates allows an efficient stabilization of the proposed systems. The paper is concluded by a detailed description of the process simulation and a comparison of its results with experimental data.