Preparation and characterization of ZTA bioceramics with and without gradient in composition

Properties and proof of suitability of homogeneously and graded ZTA bioceramics with various Y 2O 3 stabilized zirconia contents were investigated. Therefore porous alumina was infiltrated with different amounts of Y 2O 3 doped ZrO 2 precursors. At homogeneously infiltrated samples biaxial flexural strength and wear behavior were investigated (ISO 6474). Subsequently, at hip joint heads the static fracture strength was determined (ISO 7206-10). Materials ranging from approx. 4 to 20 wt% Y 2O 3 stabilized zirconia were characterized relative to the sinter density, the microstructure, the phase composition and the dispersion of the stabilized zirconia phase. Bioceramics showed high sinter density, fine microstructures, excellent wear property and significantly increased biaxial flexural strength. A 41% increase in strength through the formation of Y 2O 3 stabilized zirconia gradient in the conical bore of the heads was reached. Low compressive stresses in cone of this heads were found. ZTA bioceramics are potentially suitable for use as hip replacement components.