Direct observations and analysis of the spallation of alumina scales grown on PM2000 alloy

The spallation during cooling or thermal cycling of alumina scales grown at high temperature on PM2000 alloy is directly observed and recorded using CCD cameras. This simple and direct method permits to determine easily and accurately the scale spallation kinetics. In addition, it provides many insights on the spallation mechanisms and processes and their evolution as well as on the effect of substrate microstructure on spallation.