Critical grain size and fracture toughness of 2mol.% yttria-stabilized zirconia at ambient and cryogenic temperatures

2012 ◽  
Vol 67 (12) ◽  
pp. 963-966 ◽  
Author(s):  
Weijiang Xue ◽  
Zhipeng Xie ◽  
Jian Yi ◽  
Juan Chen
2015 ◽  
Vol 41 (3) ◽  
pp. 3888-3895 ◽  
Author(s):  
Weijiang Xue ◽  
Jian Yi ◽  
Zhipeng Xie ◽  
Chang-An Wang

2018 ◽  
Vol 57 (1) ◽  
pp. 54-62 ◽  
Author(s):  
S.V. Bobylev ◽  
A.G. Sheinerman

Abstract A model is proposed describing the effect of crack bridging on the fracture toughness of ceramic/graphene composites. The dependences of the fracture toughness on the graphene content and the sizes of the graphene platelets are calculated in the exemplary case of yttria stabilized zirconia (YSZ)/graphene composites. The calculations predict that if crack bridging prevails over crack deflection during crack growth, the maximum toughening can be achieved in the case of long graphene platelets provided that the latter do not rupture and adhere well to the matrix. The model shows good correlation with the experimental data at low graphene concentrations.


1983 ◽  
Vol 24 ◽  
Author(s):  
J. K. Cochran ◽  
K. O. Legg ◽  
H. F. Solnick-Legg

ABSTRACTSingle crystal yttria stabilized zirconia was implanted with 100 keV Ca+, Al+, and O2+ ions at fluences of 1015 to 6 × 1016 ions/cm2; . Blistering was observed at doses of 3 × 1016; O2;+ cm−2; and 6 × 1016; Al+ cm−2; but none was evident with Ca+. Knoop microhardness with a shallow indenter penetration depth peaked at a dose of 1016; ions/cm−2; for both Al+ and O2;+ but Ca+ produced no effect on microhardness. Vicker's microhardness with a much greater indenter penetration depth was not changed detectably by implantation but fracture toughness measurements from the same Vicker's indentations exhibited 10–23% increases at the highest O2+ doses and 20–25% increases at high Al+ doses. Annealing the highest implant doses at 1200° reduced the fracture toughness to pre-implant levels. Reflection electron diffraction showed that the surface had not been made amorphous by the 6 × 1016; Al+ dose as a well crystallized diffraction pattern was obtained.


Author(s):  
Hong Shen ◽  
Juan Jiang ◽  
Decai Feng ◽  
Chen Xing ◽  
Xiaofeng Zhao ◽  
...  

The crack behaviors of yttrium-stabilized zirconia during laser drilling in air, vacuum, and water environments were investigated. Due to the high stress and low fracture toughness induced by tetragonal-monoclinic phase transformation, tremendous cracks occur during drilling in air. Contrastly, cracks were reduced in vacuum drilling since the phase transformation was suppressed due to the generation of oxygen vacancies. By protection of water, no cracks were observed due to low stress and maintained fracture toughness. The crack mechanisms in different drilling media were discussed.


2011 ◽  
Vol 312-315 ◽  
pp. 894-899
Author(s):  
Sahar Salehi ◽  
Mohammad Hosseien Fathi

In this study, nanostructured composite coatings of hydroxyapatite (HA)/ 30wt% yttria stabilized zirconia (YSZ) coatings containing 0, 3, 5, and 8 mol% Y2O3 (namely; HA-0YSZ, HA-3YSZ, HA-5YSZ, and HA-8YSZ) were successfully synthesized using the sol-gel method. The crystallite size of the coating was about ~44-58 nm for tetragonal and cubic zirconia grain size and 75-87 nm for hydroxyapatite grain size. Crack-free and homogeneous HA-YSZ composite coatings were obtained with no observable defects. The uniform distribution of zirconia particles in a composite would be highly beneficial for obtaining homogeneous coatings of HA-YSZ film and would hinder grain growth of HA phase during calcinations. In vitro evaluation in 0.9% NaCl showed that Ca2+ dissolution rate of composite coatings was lower than pure HA coatings.


2017 ◽  
Vol 122 (14) ◽  
pp. 145104 ◽  
Author(s):  
Neelima Mahato ◽  
Ambreen Nisar ◽  
Pratyasha Mohapatra ◽  
Siddharth Rawat ◽  
S. Ariharan ◽  
...  

2012 ◽  
Vol 620 ◽  
pp. 35-39 ◽  
Author(s):  
Ahmad Zahirani Ahmad Azhar ◽  
Nik Akmar Rejab ◽  
Mohamad Hasmaliza ◽  
Mani Maran Ratnam ◽  
Zainal Arifin Ahmad

Fracture toughness and phases of ceramic composites produced from alumina, yttria stabilized zirconia and chromia oxide system was investigated. The Cr2O3weight percent was varied from 0 wt% to 1.0 wt%. Each batch of composition was mixed, uniaxially pressed 13mm diameter and sintered at 1600 C for 4 h in pressureless conditions. Studies on on their mechanical and physical properties such as Vickers hardness and fracture toughness were carried out. Results show that an addition of 0.6 wt% of Cr2O3produces the best mechanical properties. Results of the highest fracture toughness is 4.73 MPa.m1/2,


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
J. Wang ◽  
A. Du ◽  
Di Yang ◽  
R. Raj ◽  
H. Conrad

The grain size dependence of the bulk resistivity of 3 mol% yttria-stabilized zirconia at 1400°C was determined from the effect of a dc electric field Ea=18.1 V/cm on grain growth and the corresponding electric current during isothermal annealing tests. Employing the brick layer model, the present annealing test results were in accordance with extrapolations of the values obtained at lower temperature employing impedance spectroscopy and 4-point-probe dc. The combined values give that the magnitude of the grain boundary resistivity ρb=133 ohm-cm. The electric field across the grain boundary width was 28–43 times the applied field for the grain size and current ranges in the present annealing test.


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