Showing papers by "Patrick S. Nicholson published in 2001"
TL;DR: In this article, the compressive residual stress in the Al2O3/TZ3Y multilayer composites with strong interfaces and containing residual stresses were produced by electrophoretic deposition.
Abstract: Alumina/yttria-stablized tetragonal zirconia (Al2O3/TZ3Y) multilayer composites with strong interfaces and containing residual stresses were produced by electrophoretic deposition. As-synthesized and Vickers-indented samples with different layering designs have been tested in bending (up to 1300°C) to experimentally define conditions for crack deflection and flaw tolerance. The compressive residual stress in the Al2O3 layers (ςr) is a function of layer thickness (t). It was found that the parameter ςr2t is an effective indicator of the fracture behavior, as predicted by strain energy release calculations. With decreasing ςr2t, the fracture followed a sequence from spontaneous delamination, multistage fracture with extensive crack deflection, to catastrophic failure with, and finally without, deflection steps. Decrease of ςr with increasing test temperature causes changes in fracture behavior which correspond to the room-temperature transitions of ςr2t.
35 citations