High-temperature mechanical loss behaviour of 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP)

2003 ◽  
Vol 195 (2) ◽  
pp. 293-304 ◽  
Author(s):  
M. Daraktchiev ◽  
R. Schaller
Keyword(s):  
High Temperature ◽  
Tetragonal Zirconia ◽  
Mechanical Loss

High-temperature mechanical loss behaviour of 3 mol% yt-tria-stabilized tetragonal zirconia polycrystals (3Y-TZP)

2003 ◽  
Vol 195 (2) ◽  
pp. 289-289
Author(s):  
M. Daraktchiev ◽  
R. Schaller
Keyword(s):  
High Temperature ◽  
Tetragonal Zirconia ◽  
Mechanical Loss

High Temperature Mechanical Spectroscopy Study of 3 mol% Yttria Stabilized Tetragonal Zirconia Reinforced with Carbon Nanotubes

2012 ◽  
Vol 184 ◽  
pp. 265-270 ◽  
Author(s):  
Mehdi Mazaheri ◽  
Daniele Mari ◽  
Robert Schaller ◽  
Gilbert Fantozzi
Keyword(s):  
Carbon Nanotubes ◽  
High Temperature ◽  
High Temperatures ◽  
Tetragonal Zirconia ◽  
Grain Boundary Sliding ◽  
Mechanical Spectroscopy ◽  
Mechanical Loss ◽  
Multiwalled Carbon ◽  
Restoring Force ◽  
Low Frequencies

Composites containing 3 mol% yttria stabilized tetragonal zirconia (3Y-TZP) reinforced with multiwalled carbon nanotubes (CNTs) with various amounts of CNTs (3Y-TZP / X wt% CNT, X= 0, 0.5, 1.5, 3 and 5) were processed by spark plasma sintering. Microscopic analysis proves that CNTs were well dispersed and embedded in grain boundaries of the sintered body. High temperature mechanical properties have been investigated using mechanical spectroscopy and low stress (6 MPa) creep. The isothermal spectrum (measured at 1600 K) consists of a mechanical loss peak at a frequency of about 0.1 Hz, which is superimposed on an exponential increase at low frequency. The absence of a well-marked peak in monolithic 3Y-TZP is justified considering that restoring force decreases at low frequencies or high temperatures due to the elasticity of neighboring grains. Therefore, strain is no more restricted and the mechanical loss increases exponentially, which is correlated to macroscopic creep. However, with CNT additions the mechanical loss decreases and a better resolved peak was observed. In parallel, the results have shown that the creep rate drastically decreases with CNT additions. These results can be interpreted by the pinning effect of CNTs which can hinder grain boundary sliding at high temperatures, resulting in a creep resistance improvement.

In Situ XRD Study of Zirconia Phase Transformation Produced from Chemical and Mineral Processes

2016 ◽  
Vol 840 ◽  
pp. 375-380
Author(s):  
Meor Yusoff Meor Sulaiman ◽  
Khaironie Mohamed Takip ◽  
Ahmad Khairulikram Zahari
Keyword(s):  
High Temperature ◽  
Heating Temperature ◽  
Tetragonal Zirconia ◽  
Amorphous Structure ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Zirconyl Chloride ◽  
High Temperature Xrd ◽  
Temperature Phase Transition

The high temperature phase transition of zirconia produced from commercial zirconyl chloride chemical was compared with that produced from a Malaysian zircon mineral. Zirconyl chloride was produced from zircon by using the hydrothermal fusion method. Initial XRD diffractogram of these samples at room temperature show that they are of amorphous structure. High temperature XRD studies was then performed on these samples; heated up to 1500°C. The XRD diffractograms shows that the crystalline structure of tetragonal zirconia was first observed and the monoclinic zirconia becomes more visible at higher heating temperature.

Mechanical Properties of γ-TiAl Based Alloys at Elevated Temperatures

2000 ◽  
Vol 646 ◽  
Author(s):  
M. Weller ◽  
A. Chatterjee ◽  
G. Haneczok ◽  
F. Appel ◽  
H. Clemens
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Activation Enthalpy ◽  
Low Frequency ◽  
Loss Peak ◽  
Mechanical Loss ◽  
Creep Tests ◽  
Thermally Activated ◽  
Diffusion Controlled ◽  
Mechanical Spectra

ABSTRACTMechanical loss (internal friction) and creep experiments were carried out on specimens of a Ti-46.5at.%Al-4at.%(Cr,Nb,Ta,B) alloy with differently spaced fully lamellar microstructures. The creep tests were performed in a temperature range of 970 K to 1070 K at 175 MPa. For the mechanical loss measurements a low frequency subresonance torsion apparatus was applied, operating in the frequency range of 0.01 Hz to 10 Hz. The mechanical spectra show two phenomena: (i) A loss peak of Debye-type at 900 K (0.01 Hz) which is controlled by an activation enthalpy of 3.0 eV. The loss peak is related to thermally activated (reversible) motion of dislocation segments which are pinned at the lamellae interface and within gamma lamellae. (ii) A viscoelastic high temperature background above 1000 K with an activation enthalpy of 3.8 eV. This value agrees well with the activation enthalpy of 3.6 eV from creep experiments. Both high temperature background as well as creep are assigned to diffusion controlled climb of dislocations.

The use of Larson–Miller parameters to monitor the evolution of Raman lines of tetragonal zirconia with high temperature aging

2011 ◽  
Vol 59 (3) ◽  
pp. 1162-1167 ◽  
Author(s):  
Andi M. Limarga ◽  
Justin Iveland ◽  
Molly Gentleman ◽  
Don M. Lipkin ◽  
David R. Clarke
Keyword(s):  
High Temperature ◽  
Tetragonal Zirconia ◽  
High Temperature Aging ◽  
Temperature Aging
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