The deformation and fracture of oxide scales developed on Fe3Al, during cooling, has been modelled using finite element analysis FEA. Embedded defects have been introduced at the oxide surface and at the oxide/substrate interface and the propagation of these defects and the influence of such propagation on scale spallation has been analysed under both elastic and elastic plastic conditions. Relaxation of stresses associated with the plastic deformation of the substrate has been found to delay scale spallation and a greater temperature drop is required to cause spallation. In this situation, the presence of an oxide surface crack influences scale spallation in a complex manner. The oxide surface crack does not influence the scale spallation process for a purely linear elastic analysis, which is solely controlled by interfacial defects.
|Materials Science Forum
|Published - 2004