Repair of Ni-based single-crystal superalloys using vacuum plasma spray

• DOI: 10.1016/j.matdes.2019.107656
• Publication Date: 2019-02-13T23:23:58Z
• Authors: T. Kalfhaus; M. Schneider; B. Ruttert; D. Sebold; T. Hammerschmidt; J. Frenzel; R. Drautz; W. Theisen; G. Eggeler; O. Guillon; R. Vassen
• Keywords: Hot isostatic pressing

Turbine blades in aviation engines and land based gas-turbines are exposed to extreme environments. They suffer damage accumulation associated with creep, oxidation fatigue loading. Therefore, advanced repair methods of special interest for the gas-turbine industry. In this study, CMSX-4 powder is sprayed by Vacuum Plasma Spray (VPS) on single-crystalline substrates similar compositions. The influence substrate temperature investigated altering heating stage between 850 °C 1000 °C. Different spray parameters were explored identify their microstructure. Hot isostatic pressing (HIP) featuring fast quenching rates was used minimize porosity allow well-defined heat-treatments coatings. microstructure analysed orientation imaging scanning electron microscopy (SEM), using backscatter diffraction (EBSD). effects different processing regarding grain size. results show that optimized HIP can lead dense coatings optimum γ/γ′ interface coating oxide free shows good mechanical integrity. formation fine crystalline regions as a result cooling observed at single-crystal surface, which resulted growth during heat-treatment orientations determined crystallography substrate.