Evaluation of Fracture Toughness Determination Methods as Applied to Ceria-Stabilized Tetragonal Zirconia Polycrystal

1987 ◽  
Vol 70 (12) ◽  
pp. C-366-C-368 ◽  
Author(s):  
Roger L. K. Matsumoto
Keyword(s):  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
Determination Methods ◽  
Tetragonal Zirconia Polycrystal

Effect of TiN Addition on Microstructure and Mechanical Properties of Zirconia Matrix Ceramic Tool Material

2004 ◽  
Vol 471-472 ◽  
pp. 321-325 ◽  
Author(s):  
Jing Sun ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Sui Lian Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Monoclinic Phase ◽  
Tetragonal Zirconia ◽  
Tool Material ◽  
Strengthening Mechanisms ◽  
Microstructure And Mechanical Properties ◽  
Ceramic Tool Material ◽  
Tetragonal Zirconia Polycrystal

In this paper, 3mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) and TiN/3Y-TZP(adding TiN particles to 3Y-TZP) composites were fabricated by hot-pressing technique. Phase composition, microstructure and mechanical properties of the composites were investigated. It is shown that the flexural strength, fracture toughness and Vickers hardness of TiN/3Y-TZP was significantly improved by the addition of TiN particles compared with 3Y-TZP. The flexural strength of ZYT2 (20wt% TiN addition) is 1318 MPa. The fracture toughness of ZYT4 (40wt% TiN addition) is 16.8MPa·m1/2. The toughening and strengthening mechanisms were analyzed. The XRD results show that the additing of TiN can hinder the transformation from tetragonal phase to monoclinic phase of 3Y-TZP during fabrication process.

Laser-Assisted Milling of Zirconia with Systematically Determined Machining Conditions

2017 ◽  
Vol 11 (2) ◽  
pp. 258-269
Author(s):  
Toru Kizaki ◽  
◽  
Yusuke Ito ◽  
Naohiko Sugita ◽  
Mamoru Mitsuishi
Keyword(s):  
Fracture Toughness ◽  
Unique Feature ◽  
Elevated Temperatures ◽  
Thrust Force ◽  
Tetragonal Zirconia ◽  
Systematic Method ◽  
Processing Efficiency ◽  
Diamond Tools ◽  
Dental Restoratives ◽  
Tetragonal Zirconia Polycrystal

Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is a promising material for dental restoratives. Although grinding or polishing with diamond tools is widely used to machine Y-TZP, the processing efficiency and cost of the process are problematic. In this study, we applied laser-assisted machining (LAM) to Y-TZP, in which non-diamond tools were used. Unlike LAM applied to other materials, decrease of the fracture toughness at elevated temperatures which is a unique feature of the Y-TZP was adopted as a key mechanism for machinability enhancement. In addition, a systematic method to determine the LAM conditions was proposed. In this study, we explain the LAM condition-determining method, which is based on numerical simulations of the temperature distribution. Secondly, the determining method was evaluated through a series of LAM experiments to obtain the appropriate LAM conditions. Using the determined conditions, LAM of Y-TZP was demonstrated to be effective; the thrust force was reduced by 51.3% and the tool wear was significantly reduced, while no cracks formed on the Y-TZP.

scholarly journals Determination of Hardness and Fracture Toughness of Y-TZP Manufactured by Digital Light Processing through the Indentation Technique

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ziyu Mei ◽  
Yuqing Lu ◽  
Yuxin Lou ◽  
Ping Yu ◽  
Manlin Sun ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
Milling Process ◽  
Control Group ◽  
Digital Light Processing ◽  
Hardness Values ◽  
3D Printing Technique ◽  
True Hardness ◽  
Tetragonal Zirconia Polycrystal

Objective. The purpose of the study was to determine the hardness and fracture toughness of dental yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) manufactured by digital light processing (DLP) technology to study its clinical prospects. Methods. The experimental group was DLP-manufactured zirconia, and the control group was milled zirconia. The hardness was investigated under a range of test loads (0.49 N, 0.98 N, 1.96 N, 4.90 N, 9.81 N, 29.42 N, 49.03 N, 98.07 N, and 196.1 N). Meyer’s law was applied to describe the indentation size effect (ISE). Meanwhile, the PSR model and MPSR model were utilized to generate true hardness values. The cracks were observed to be induced by indentation under loads above 49.03 N, while the cracks showed the radial-median type under the load of 196.1 N, under which the fracture toughness was calculated. Results. The true hardness of DLP-manufactured zirconia was 1189 HV based on the PSR model and 1193 HV based on the MPSR model, a bit lower than that of milled zirconia. The fracture toughness was 3.43 ± 0.29   MPa √ m , which showed no statistical difference with the milled zirconia. Conclusion. The dental zirconia manufactured by the DLP 3D printing technique is similar to that manufactured by the conventional milling process in hardness and fracture toughness, thus having a promising future of clinical use.

Sinterability of Alumina-Dispersed 3Y-TZP

2006 ◽  
Vol 317-318 ◽  
pp. 37-40
Author(s):  
Bum Rae Cho ◽  
Dong Guk Yeoum
Keyword(s):  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
Micro Hardness ◽  
Drying Method ◽  
Hardness Tester ◽  
Pinning Effect ◽  
High Relative Density ◽  
Al2o3 Particles ◽  
Vickers Micro Hardness ◽  
Tetragonal Zirconia Polycrystal

The effect of Al2O3 addition on sinterability of Tetragonal Zirconia Polycrystal powders including 3mol% Y2O3 (3Y-TZP) was investigated. Each 3Y-TZP powder dispersed with 0.3, 0.6, 0.9 and 1.2wt.% of Al2O3 was prepared by the spray-drying method. The prepared powders were pressed into a disk type and sintered at 1350, 1400, 1450 and 1500 for 2 hours in the air. Resultant microstructures and mechanical properties of specimens were investigated by using Vickers/Micro hardness Tester, FE-SEM and XRD. Most of the specimens showed high relative density over 99% and a higher fracture toughness than pure 3Y-TZP. Al2O3 particles dispersed in 3Y-TZP microstructure depressed grain growth of 3Y-TZP by the pinning effect. Increase in fracture toughness of 3Y-TZP was explained by the crack deflection due to dispersed Al2O3 particles.

Behavior of 3mol% yttria-stabilized tetragonal zirconia polycrystal film prepared by slurry spin coating

2009 ◽  
Vol 186 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Kongfa Chen ◽  
Yanting Tian ◽  
Zhe Lü ◽  
Na Ai ◽  
Xiqiang Huang ◽  
...  
Keyword(s):  
Spin Coating ◽  
Tetragonal Zirconia ◽  
Tetragonal Zirconia Polycrystal

Transformation behavior of yttria stabilized tetragonal zirconia polycrystal–TiB2 composites

2001 ◽  
Vol 16 (7) ◽  
pp. 2158-2169 ◽  
Author(s):  
B. Basu ◽  
J. Vleugels ◽  
O. Van Der Biest
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Low Temperature ◽  
Tetragonal Zirconia ◽  
Mechanical Analysis ◽  
Transformation Behavior ◽  
Thermal Expansion Data ◽  
Thermally Induced ◽  
First Time ◽  
Tetragonal Zirconia Polycrystal

The objective of the present article is to study the influence of TiB2 addition on the transformation behavior of yttria stabilized tetragonal zirconia polycrystals (Y-TZP). A range of TZP(Y)–TiB2 composites with different zirconia starting powder grades and TiB2 phase contents (up to 50 vol%) were processed by the hot-pressing route. Thermal expansion data, as obtained by thermo-mechanical analysis were used to assess the ZrO2 phase transformation in the composites. The thermal expansion hysteresis of the transformable ceramics provides information concerning the transformation behavior in the temperature range of the martensitic transformation and the low-temperature degradation. Furthermore, the transformation behavior and susceptibility to low-temperature degradation during thermal cycling were characterized in terms of the overall amount and distribution of the yttria stabilizer, zirconia grain size, possible dissolution of TiB2 phase, and the amount of residual stress generated in the Y-TZP matrix due to the addition of titanium diboride particles. For the first time, it is demonstrated in the present work that the thermally induced phase transformation of tetragonal zirconia in the Y-TZP composites can be controlled by the intentional addition of the monoclinic zirconia particles into the 3Y-TZP matrix.

scholarly journals Effect of Al2O3 Sandblasting Particle Size on the Surface Topography and Residual Compressive Stresses of Three Different Dental Zirconia Grades

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 610
Author(s):  
Hee-Kyung Kim ◽  
Byungmin Ahn
Keyword(s):  
Particle Size ◽  
Residual Stresses ◽  
Surface Topography ◽  
Tetragonal Zirconia ◽  
Peak Shift ◽  
Confocal Laser ◽  
Compressive Stresses ◽  
Surface Topographies ◽  
Altered Surface ◽  
Tetragonal Zirconia Polycrystal

This study investigated the effect of sandblasting particle size on the surface topography and compressive stresses of conventional zirconia (3 mol% yttria-stabilized tetragonal zirconia polycrystal; 3Y-TZP) and two highly translucent zirconia (4 or 5 mol% partially stabilized zirconia; 4Y-PSZ or 5Y-PSZ). Plate-shaped zirconia specimens (14.0 × 14.0 × 1.0 mm3, n = 60 for each grade) were sandblasted using different Al2O3 sizes (25, 50, 90, 110, and 125 μm) under 0.2 MPa for 10 s/cm2 at a 10 mm distance and a 90° angle. The surface topography was characterized using a 3-D confocal laser microscopy and inspected with a scanning electron microscope. To assess residual stresses, the tetragonal peak shift at 147 cm−1 was traced using micro-Raman spectroscopy. Al2O3 sandblasting altered surface topographies (p < 0.05), although highly translucent zirconia showed more pronounced changes compared to conventional zirconia. 5Y-PSZ abraded with 110 μm sand showed the highest Sa value (0.76 ± 0.12 μm). Larger particle induced more compressive stresses for 3Y-TZP (p < 0.05), while only 25 μm sand induced residual stresses for 5Y-PSZ. Al2O3 sandblasting with 110 μm sand for 3Y-TZP, 90 μm sand for 4Y-PSZ, and 25 μm sand for 5Y-PSZ were considered as the recommended blasting conditions.

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