Fracture toughness and surface morphology of Al2O3/Pt composites

In the present study, Al2O3-based composites with dispersed Pt particles were prepared by using a reduction-precipitation method. Particle distribution, fracture toughness, and morphology of the prepared Al2O3/Pt composites were studied. Crystal structure of the composites was evaluated by analyzing Pt characteristic peaks in the X-ray diffraction spectra. Transmission electron microscopy images indicated that the Pt particles were uniformly dispersed in the Al2O3 powder. The fracture toughness of the Al2O3 matrix was improved by the addition of Pt particles, since these particles effectively resisted crack propagation in the Al2O3/Pt composites. Scanning electron microscopy images indicated that the fracture of the composites followed an intergranular mechanism, typical of ceramic materials, at low Pt content, whereas a transgranular mechanism occurred at high Pt content.

The fracture surface showed an intergranular mechanism of fracture, typical of ceramic materials, at low Pt content, and a transgranular mechanism at high Pt content.Figure optionsDownload as PowerPoint slide