Sinter-Forging of Nanocrystalline Zirconia: II, Simulation

2004 ◽  
Vol 82 (3) ◽  
pp. 545-555 ◽  
Author(s):  
Douglas C. Hague ◽  
Merrilea J. Mayo
Keyword(s):  
Sinter Forging ◽  
Nanocrystalline Zirconia

Annealing effects on phase transformation and powder microstructure of nanocrystalline zirconia polymorphs

1999 ◽  
Vol 14 (1) ◽  
pp. 90-96 ◽  
Author(s):  
R. Ramamoorthy ◽  
S. Ramasamy ◽  
D. Sundararaman
Keyword(s):  
Monoclinic Phase ◽  
Lattice Strain ◽  
Dopant Concentration ◽  
Precipitation Method ◽  
Strain Effect ◽  
Volume Percentage ◽  
Annealing Temperatures ◽  
Annealing Effects ◽  
Nanocrystalline Zirconia ◽  
Average Size

Nanocrystalline zirconia powders in pure form and doped with yttria and calcia were prepared by the precipitation method. In the as-prepared condition, all the doped samples show only monoclinic phase, independent of the dopants and dopant concentration. On annealing the powders at 400 °C and above, in the case of 3 and 6 mol% Y2O3 stabilized ZrO2 (3YSZ and 6YSZ), the monoclinic phase transforms to tetragonal and cubic phases, respectively, whereas in 3 and 6 mol% CaO stabilized ZrO2 (3CSZ and 6CSZ), the volume percentage of the monoclinic phase gradually decreases up to the annealing temperature of about 1000 °C and then increases for higher annealing temperatures. The presence of monoclinic phase in the as-prepared samples of doped zirconia has been attributed to the lattice strain effect which results in the less symmetric lattice. For the annealing temperatures below 1000 °C, the phenomenon of partial stabilization of the tetragonal phase in 3CSZ and 6CSZ can be explained in terms of the grain size effect. High resolution transmission electron microscopy (HRTEM) observations reveal the lattice strain structure in the as-prepared materials. The particles are found to be a tightly bound aggregate of small crystallites with average size of 10 nm. The morphology of the particles is observed to be dependent on the dopants and dopant concentration.

Nanocrystalline Zirconia Surface-Doped with Alumina: Chemical Vapor Synthesis, Characterization, and Properties

2001 ◽  
Vol 84 (12) ◽  
pp. 2771-2776 ◽  
Author(s):  
Vladimir V. Srdić ◽  
Markus Winterer ◽  
Andreas Möller ◽  
G. Miehe ◽  
Horst Hahn
Keyword(s):  
Chemical Vapor ◽  
Chemical Vapor Synthesis ◽  
Nanocrystalline Zirconia

Nanocrystalline zirconia: A novel sorbent for the preparation of 188W/188Re generator

2010 ◽  
Vol 68 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Rubel Chakravarty ◽  
Rakesh Shukla ◽  
A.K. Tyagi ◽  
Ashutosh Dash ◽  
Meera Venkatesh
Keyword(s):  
Nanocrystalline Zirconia

Preparation of Porous Ceramics from Nanocrystalline Zirconia and Their Microstructure

2004 ◽  
Vol 40 (7) ◽  
pp. 760-763 ◽  
Author(s):  
D. S. Nikitin ◽  
V. A. Zhukov ◽  
V. V. Perkov ◽  
S. P. Buyakova ◽  
S. N. Kul'kov
Keyword(s):  
Porous Ceramics ◽  
Nanocrystalline Zirconia

The EXAFS study of nanocrystalline zirconia

1994 ◽  
Vol 6 (3) ◽  
pp. 633-640 ◽  
Author(s):  
Wang Yuren ◽  
Lu Kunquan ◽  
Wang Dazhi ◽  
Wu Zhonghua ◽  
Fang Zhengzhi
Keyword(s):  
Exafs Study ◽  
Nanocrystalline Zirconia

Microwave-Hydrothermal Synthesis of Nanocrystalline Zirconia Powders

2001 ◽  
Vol 84 (11) ◽  
pp. 2728-2730 ◽  
Author(s):  
Federica Bondioli ◽  
Anna Maria Ferrari ◽  
Cristina Leonelli ◽  
Cristina Siligardi ◽  
Gian Carlo Pellacani
Keyword(s):  
Hydrothermal Synthesis ◽  
Microwave Hydrothermal ◽  
Nanocrystalline Zirconia ◽  
Zirconia Powders

Microhardness Enhancement in Fully Dense Fe-Based Nanophase Metallic Alloys

1995 ◽  
Vol 400 ◽  
Author(s):  
L. He ◽  
E. Ma
Keyword(s):  
Grain Size ◽  
High Energy ◽  
Metallic Alloys ◽  
Full Density ◽  
Strengthening Effect ◽  
Two Phase ◽  
Grain Sizes ◽  
Sinter Forging ◽  
Interphase Boundaries ◽  
Energy Ball

AbstractNano-grained Fe-29Al-2Cr intermetallic and Fe-Cu two-phase composites have been consolidated to full density from powders produced by high-energy ball milling, using a sinter forging procedure developed recently in our laboratory. Grain sizes remained within nanophase range (<100 nm) after consolidation. Microhardness tests of Fe-29Al-2Cr samples consolidated to different density levels indicate a significant strengthening effect due to nanoscale grain size and a monotonic microhardness increase with decreasing residual porosity. Fully dense Fe-Cu composites exhibit enhanced microhardness as compared with rule-of-mixtures predictions, which may be attributable to interface strengthening at fcc-bcc interphase boundaries.

Sign in / Sign up

Export Citation Format

Share Document