ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The microstructures in 3 mol% Y2O3-stabilized tetragonal zirconia polycrystal (Y-TZP)sintered at 1100°-1650°C were investigated to clarify cubic-formation and grain-growthmechanisms. The cubic phase in Y-TZP appeared at 1300°C and its mass fraction increased withincreasing sintering temperature. High-resolution transmission electron microscopy (HRTEM) andnanoprobe X-ray energy dispersive spectroscopy (EDS) measurements revealed that no amorphouslayer existed along the grain-boundary faces in Y-TZP, and Y3+ ions segregated not only along thetetragonal-tetragonal phase boundaries but also along tetragonal-cubic phase boundaries. Scanningtransmission electron microscopy (STEM) and nanoprobe EDS measurements revealed that the Y3+ion distribution was nearly homogeneous up to 1300°C, but cubic phase regions with high Y3+ ionconcentration clearly formed inside grains at 1500°C. These results indicate that cubic phase regionsare formed from the grain boundaries and/or the multiple junctions in which Y3+ ions segregated. Wetermed such a new diffusive transformation phenomenon “grain boundary segregation-inducedphase transformation (GBSIPT)”. The grain-growth mechanism is controlled by the solute-drageffect of Y3+ ions segregating along the grain boundary
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/17/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.558-559.921.pdf
