Titanium Effect on Microstructure and Fracture toughness of Al2O3-BASED Composites
The effect of different titanium additions (0.5, 1, 2, 3 and 10 vol. %), milling intensity (4 and 8 h) and sintered temperature (1500 and 1600 °C) on microstructure and fracture toughness of Al2O3-based composites was analyzed in this study. After high energy milling of a titanium and Al2O3 mixtures, powder mixture presents fine distribution and good homogenization between ceramic and metal. After milling powders during 8 h they were obtained very fine particles with 200 nm average sizes. Microstructures of the sintered bodies were analyzed with a scanning electron microscopy, where it was observed that the microstructure presents the formation of a small and fine metallic net inside the ceramic matrix. From fracture toughness measurements realized by the fracture indentation method, it had that when titanium content in the composite increases, fracture toughness is enhanced until 83% with respect to the fracture toughness of pure Al2O3. This behavior is due to the formation of metallic bridges by titanium in the Al2O3 matrix.
J. Federico Chávez Alcalá, Alejandro Cruz Ramírez and Ma. de los Ángeles Hernández Pérez
J. G. Miranda-Hernández et al., "Titanium Effect on Microstructure and Fracture toughness of Al2O3-BASED Composites", Materials Science Forum, Vol. 691, pp. 32-36, 2011