Abstract
Commercially available alumina ceramic Al24 containing 5% porosity was alloyed by adding HfO 2 or mixtures of HfO 2 with 5 or 10 mol% SiO 2, CeO 2 or cordierite glass using infrared laser radiation. Thickness of the alloyed surfaces ranged between 500 and 800 μm depending on the composition of the alloyed powders and laser parameters used. The resulting microstructures and worn surfaces were analysed by electron microscopy. As a result of the alloying, the tendency of crack formation and grain growth was substantially reduced in the Al 2O 3 ceramic during laser treatment. The composite layers, showing no open porosity, contained 20–40 vol.% second phases, which were homogeneously distributed at the grain boundaries of the alumina matrix. Due to alloying, average grain size, hardness and Young's modulus of the composite layers were reduced, but resistance to cracking under the mechanical action of a sliding diamond (scratch test) abrasive wearing were substantially enhanced compared with the unmodified dense alumina ceramics Al23.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
