Texture in superplastically deformed alumina–zirconia composites

Abstract

3Y-TZP/Al 2O 3 composites were prepared by hot-pressed sintering at 1450 °C for 1 h under 30 MPa in vacuum, and then the fine-grained composite sintered bodies were deformed by superplastic compression at 1500 °C. Quantitative texture analysis to the hot-pressed and deformed composites was accomplished via XRD and X-ray pole figure measurements. Highly oriented and textured microstructure was generated by superplastic deformation. The maximum degree of texture was up to 7.3 times random. The microstructure observation based on SEM and TEM was adopted to explain the development and mechanism of texture formation. The results indicated that Al 2O 3 matrix with fine platelike grains was formed in deformed materials, while the shape of ZrO 2 grains did not change obviously. The predominant mechanism for deformation and texture development was grain-boundary sliding and grain rotation, accompanying with anisotropic grain growth. Meanwhile, the intragranular dislocation motion played an important role in the formation of texture.