Abstract
This work demonstrates the capabilities of oxide dispersion strengthened MCrAlY coatings and the process used to produce the feedstock powders. Mechanically alloyed powder mixtures were prepared in a high-energy ball mill using commercial NiCoCrAlY and YPSZ powders combined in different amounts. A high-velocity oxyfuel torch was used to deposit the powders on Inconel substrates that were then heat treated for 6 h at 1050 °C. Samples were also produced from unaltered NiCoCrAlY powder to serve as a reference. In high-temperature erosion tests, the strengthened coatings had a mass loss of 47 mg/cm2 after 30 sec compared to 38 mg/cm2 for the unstrengthened sample. High-temperature corrosion tests showed that the strengthened coatings were not dense enough to protect the substrate from oxidation. The hard phases inhibited sintering and diffusion effects during heat treatment. As a result, dislocations, defects, and voids could not move and were used by oxygen for diffusion. In further investigations, the strengthened coatings will be treated at a higher temperature to achieve a better sintering effect.
