Structure-property relationship of a nickel-based honeycomb sealing composite

Since brittle intermetallic compounds can form during soldering of nickel-based alloys, the microhardness in the area of the solder material is increased. This can be observed when joining thin-walled honeycomb structures. They are used as stationary component in sealing systems of gas turbine engines. Both the increase in the microhardness and the volume fraction of the solder material are assumed to threaten the integrity of the rotating sealing component if contact (rubbing) between the two components occurs during engine operation. To predict the impact of the solder material on the structure-property relationship of the nickel-based honeycomb structure, a micromechanical modelling approach is presented in this work. The three-dimensional micromechanical modelling approach comprises a composite of two distinct materials, the cell-wall and the solder material. The constitutive behaviour of the ductile cell-wall material is modelled with a crystal plasticity approach. A purely elastic material behaviour is assumed for the brittle solder material. For an efficient simulation, the investigated domain is restricted to the unit cell of the honeycomb composite. The studies show that with increasing volume fraction of the solder material, both thermal and mechanical loads of the honeycomb composite increase significantly, raising the likelihood of damage to the material of the rotating sealing component.