Net shape manufacturing of CuCr for vacuum interrupters

Finite element based simulation methods and continuum mechanics based modeling are commonly proved to represent cost efficient and timesaving tools for optimization of filling body geometries and tool designs. In case of adequate material descriptions they also allow to reduce the risk of flaws such as formation of cracks and low-density areas, respectively. Further enhancements such as minimized sintering distortions are achievable by linking the simulation tools for compaction and sintering forming the basis for an advanced design tool of Net Shape (NS) manufacturing routes. The economic relevance and technical applicability of the proposed approach is demonstrated on the example of Net Shape manufactured CuCr contacts for medium voltage circuit breakers as they are used in electric power distribution. The approach comprises modeling of powder compaction and sintering in an integrative manner via Drucker-Prager/Cap plasticity modeling and non- linear visco-elastic transversally isotropic sintering modeling, respectively. In particular, the careful calibration procedure for the material models used for the compaction and sintering regime with respect to the experimental findings of several types of mechanical green body tests as well as sintering experiments is described in detail. This way the presented approach claims and focuses on the first-in-class show case of a CuCr vacuum interrupter component being Net Shape manufactured.