The effect of phase composition on the transport properties of composites La0.8Sr0.2Fe0.7Ni0.3O3 − δ-Ce0.9Gd0.1O1.95

2011 ◽  
Vol 47 (6) ◽  
pp. 663-670 ◽  
Author(s):  
Yu. S. Okhlupin ◽  
M. V. Ananyev ◽  
N. F. Uvarov ◽  
Yu. N. Bespalko ◽  
S. N. Pavlova ◽  
...  
Keyword(s):  
Phase Composition ◽  
Transport Properties ◽  
Properties Of Composites

Structure, phase composition and mechanical properties of composites based on ZrO2 and multi-walled carbon nanotubes

2020 ◽  
Vol 10 ◽  
pp. 56-68
Author(s):  
A. A. Leonov ◽  
◽  
E. V. Abdulmenova ◽  
M. P. Kalashnikov ◽  
◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Phase Composition ◽  
Zirconium Carbide ◽  
Cubic Phase ◽  
Plasma Sintering ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Walled Carbon Nanotubes ◽  
Tetragonal Phase Transition ◽  
Properties Of Composites

In this work, composites based on yttria-stabilized zirconia (3Y-TZP), with additives of 1, 5 and 10 wt. % multi-walled carbon nanotubes (MWCNTs) were investigated. Samples were obtained by spark plasma sintering at a temperature of 1500 °C. It was found that MWCNTs retain their structure after high-temperature sintering, they are located along the grain boundaries of ZrO2, forming a network structure. Found that the addition of 1 wt. % MWCNTs increase the relative density of the composite from 98.3 % to 99.0 %. It is noted that nanotubes can significantly affect the phase composition of composites. Additive 5 wt. % MWCNT partially limits the monoclinic-tetragonal phase transition of ZrO2, and the addition of 10 wt. % MWCNTs leads to the formation of a cubic phase of zirconium carbide. It was found that the fracture toughness of the composite with 10 wt. % MWCNTs increases from 4.0 to 5.7 MPa·m1/2.

Effect of Al2O3 nanofibers on compaction, phase composition, and mechanical properties of ZrO2-based composites obtained by vacuum pressureless sintering

2021 ◽  
pp. 132-143
Author(s):  
A. A. Leonov ◽  
E. V. Abdulmenova ◽  
M. P. Kalashnikov ◽  
Jing Li
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Crack Resistance ◽  
Physicomechanical Properties ◽  
Relative Content ◽  
Pressureless Sintering ◽  
Vacuum Sintering ◽  
Tetragonal Modification ◽  
Different Content ◽  
Properties Of Composites

This work studies the effect of the relative content of Al2O3 nanofibers on the compaction, phase composition, and physicomechanical properties of composites based on ZrO2 obtained by free vacuum sintering. It was found that in the process of manufacturing composites, nanofibers are sintered into Al2O3 grains of complex, elongated shape, which form a solid, frame-reinforcing structure. The relative density of composites with 5 wt. % and 10 wt. % of nanofibers, decreases up to 95%. It is shown that in all sintered samples the tetragonal modification of ZrO2 acts as the main phase, and the different content of nanofibers affects the amount of cubic and monoclinic modifications of ZrO2. It was found that addition of 5 wt. % and 10 wt. % of Al2O3 nanofibers increases the microhardness of the composite by 11% and crack resistance by 46%.

Optimal Percolation Thresholds of Two- and Three-Dimensional Engineering Composites

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
X. Frank Xu
Keyword(s):  
Thin Films ◽  
Variational Method ◽  
Theoretical Prediction ◽  
Transport Properties ◽  
Three Dimensional ◽  
Engineering Applications ◽  
Aspect Ratios ◽  
Percolation Thresholds ◽  
Work Done ◽  
Properties Of Composites

Theoretical prediction of percolation thresholds universally applicable for various composites remains a major theoretical challenge. In the work done by Xu (2011, “Ellipsoidal Bounds and Percolation Thresholds of Transport Properties of Composites,” Acta Mech., 223, pp. 765–774), a variational method is developed to predict optimal percolation thresholds for transport properties of three dimensional composites subjected to full dispersion of fillers. In this paper, simplified formulae are provided for engineering applications of 3D composites. New formulae are derived for optimal percolation thresholds of 2D composites, i.e., laminates and thin films, and for composites containing a combination of fillers with different aspect ratios. The effects of dimensionality and waviness are especially discussed.

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