Effect of microscale shear stresses on the martensitic phase transformation of nanocrystalline tetragonal zirconia powders

Mette Skovgaard, Anwar Ahniyaz, Bent F. Sørensen, Kristoffer Almdal, Alexander van Lelieveld

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    For the first time, the effect of microscale shear stress induced by both mechanical compression and ball-milling on the phase stability of nanocrystalline tetragonal zirconia (t-ZrO2) powders was studied in water free, inert atmosphere. It was found that nanocrystalline t-ZrO2 powders are extremely sensitive to both macroscopic uniaxial compressive strain and ball-milling induced shear stress and easily transform martensitically into the monoclinic phase. A linear relationship between applied compressive stress and the degree of tetragonal to monoclinic (t → m) phase transformation was observed. Ball-milling induced microscale stress has a similar effect on the t → m phase transformation. Furthermore, it was found that even very mild milling condition, such as 120 rpm, 1 h (0.5 mm balls) was enough to induce phase transformation. Surfactant assisted ball-milling was found to be very effective in de-agglomeration of our nanocrystalline porous ZrO2 particles into discrete nanocrystals. However, the t → m phase transformation could not be avoided totally even at very mild milling condition. This suggests that the metastable t-ZrO2 is extreme sensitive to microscale shear stress induced by both mechanical compression and ball-milling. The findings presented in this work are very important in further understanding the stress-induced phase transformation of nanocrystalline t-ZrO2 powders in a water free atmosphere and their further stabilization in industrially relevant solvents.
    Original languageEnglish
    JournalJournal of the European Ceramic Society
    Volume30
    Issue number13
    Pages (from-to)2749-2755
    ISSN0955-2219
    DOIs
    Publication statusPublished - 2010

    Keywords

    • Materials and energy storage
    • Lette stærke materialer til energiformål
    • Light strong materials for energy purposes

    Fingerprint Dive into the research topics of 'Effect of microscale shear stresses on the martensitic phase transformation of nanocrystalline tetragonal zirconia powders'. Together they form a unique fingerprint.

    Cite this