Direct Examinations of Oxide Scales upon Cooling: A New Way to Analyse Oxide Scale Spallation

摘要: The spallation behaviour of thick alumina scale grown at 1300 degreesC on PM2000 alloy was investigated by recording the events occurring upon cooling from down to ambient temperature with CCD cameras. evolutions spalled surface fraction time and as well trajectories particles were observed analysed. These observations analysis used determine critical temperatures drops incubation times for onset calculate kinetic energies oxide which is a part energy balance describing interfacial decohesion, fracture finally scales. In addition usual phenomenon resulting in ejection small but measurable spalls, localized sudden outbursts very fine powders also observed, showing that likely more complex than usually considered.