Microstructure and mechanical properties of solid AL2O3-ZRO2 (Y2O3) eutectics prepared by laser engineered net shaping

High dense Al2O3-ZrO2 (Y2O3) eutectics were directly prepared based on the raw material of Al2O3-ZrO2 (Y2O3) ceramic powders by laser engineered net shaping. The microstructure, the microhardness, and the fracture toughness of Al2O3-ZrO2 (Y2O3) eutectics were evaluated. The compact cellular eutectic with the nanosize microstructure and the homogeneous dispersion of zirconia fibers embedded in the continuous Al2O3 matrix were obtained, and the periodic coarsening banded structure perpendicular to the deposition direction produced due to the layer-by-layer shaping style. Testing results showed that the microhardness of eutectic ceramic was 17.15 +/- 0.4 GPa, the actual density was 4.407 g/cm(3), and the relative destiny reached up to 98.3%. In addition, the fracture toughness value in the coarsening banded region was 4.79 +/- 0.3 MPa.m(1/2), and the region with the nanosize microstructure eutectic had the fracture toughness value 3.71 +/- 0.3 MPa.m(1/2). The coarsening banded region had the higher fracture toughness than that with the nanosize microstructure eutectic, which was because the large eutectic spacing would reinforce the compressive stress toughening mechanism. (C) 2017 Laser Institute of America.