To investigate the local creep properties indentation creep testing is a well-suited technique for combinatorial investigations of alloys, since it allows an examination of the local creep properties at elevated temperatures. A new approach with a 20 µm cylindrical flat punch has been developed to allow measurements on the micrometer scale in a thermomechanical analyser and this approach was used to investigate the influence of the Cr-content on the creep properties of a multinary CoNi-base superalloy CoWAlloy2 by conducting indentation creep experiments on a diffusion couple of CoWAlloy2 and a derivate of CoWAlloy2 with significantly increased Cr-content.

The indentation creep experiments were complemented with SEM investigations and nanoindentation hardness measurements to correlate the microstructure, hardness and the creep properties with the local chemical composition. It could be concluded that the γ' volume fraction decreases and additional phases form at high Cr concentrations. The hardness measurements and indentation creep experiments indicated that a slight increase of the Cr-content could increase the creep strength. In summary, this study presents an integrated approach for a combinatorial materials research on a multinary γ/γ' Co-base superalloy.