Yttria stabilized zirconia (YSZ)/Al2O3 Composite coatings were prepared by an electrophoretic deposition (EPD) method. The mechanical properties of the coatings were determined by nanoindentation and residual stresses were measured by Cr3+ fluorescence spectroscopy. It was found that the nanoindentation was sensitive to the presence of sub-micrometer pores. In order to determine the macroscopic mechanical properties, a penetration depth of >1000 run was required due to the porous and inhomogeneous nature of the materials. Both microstress and mechanical properties exhibited a gradient across the coating thickness, which can be attributed to the density gradient caused by constrained sintering of the coatings. It has been confirmed that the mechanical properties determined by nanoindentation are not affected by the external applied stress. AFM examination confirmed there was no impression pile-up during indentation. (c) 2005 Elsevier B.V. All rights reserved.