Influence of Sintering Temperature on the Translucency of Sintered Zirconia by Cold Isostatic Pressing

2014 ◽  
Vol 896 ◽  
pp. 591-595
Author(s):  
Chuin Hao Chin ◽  
Andanastuti Muchtar ◽  
Noor Faeizah Amat ◽  
Mariyam Jameelah Ghazali ◽  
Norziha Yahaya
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Tetragonal Zirconia ◽  
Hardness Test ◽  
Cold Isostatic Pressing ◽  
Light Transmittance ◽  
Isostatic Pressing ◽  
Different Temperatures ◽  
Pellet Form ◽  
Dental Applications

Zirconia-based ceramics exhibit excellent mechanical properties and biocompatibility in dental applications. However, the production of translucent zirconia that offers resemblance to real teeth remains a challenge. This study aims to fabricate zirconia compacts by cold isostatic pressing (CIP) and investigate the influence of sintering temperature on translucency, microstructure, hardness, and density of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). Zirconia stabilized with 3 mol% yttria (3Y-TZP) was pressed by uniaxial pressing and later by CIP to produce green bodies in pellet form. Subsequently, the green bodies were sintered at different temperatures (1100 °C to 1300 °C). The specimens were then investigated in terms of translucency, density, and hardness. X-ray diffraction was also performed and the microstructure of the specimens was observed under a scanning electron microscope (SEM). Density and light transmittance tests results showed that zirconia sintered at 1200 °C exhibits the highest density (5.957 g/cm3) and light transmittance intensity. Vickers hardness test showed that higher sintering temperatures result in higher hardness of the sintered zirconia. SEM micrographs illustrate the effect of microstructural changes on the translucency of zirconia. A temperature of 1200 °C is found to be the recommended sintering temperature at which zirconia exhibiting optimum translucency and mechanical properties is produced. CIP is found to be a suitable consolidation method to produce high-density translucent zirconia.

Effect of Sintering Temperature on the Mechanical Properties of Nanostructured Ceria-Zirconia Prepared by Colloidal Process

2015 ◽  
Vol 1125 ◽  
pp. 401-405
Author(s):  
Mohamed M. Aboras ◽  
Andanastuti Muchtar ◽  
Noor Faeizah Amat ◽  
Che Husna Azhari ◽  
Norziha Yahaya
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Slip Casting ◽  
Tetragonal Zirconia ◽  
Cold Isostatic Pressing ◽  
Sintering Process ◽  
Colloidal Processing ◽  
Tooth Color ◽  
Biological Compatibility ◽  
Nanostructured Ceria

The demand for tetragonal zirconia as a dental restorative material has been increasing because of its excellent mechanical properties and resemblance to natural tooth color, as well as its excellent biological compatibility. Cerium oxide (CeO2) has been added to yttria-stabilized zirconia (Y-TZP), and studies have demonstrated that the stability of the tetragonal phase can be significantly improved. Y-TZP with 5wt% CeO2 as a second stabilizer was developed via colloidal process, followed by a suitable sintering process. According to the literature, the sintering process is the most crucial stage in ceramic processing to obtain the most homogeneous structure with high density and hardness. This study aims to investigate the effect of sintering temperature on the mechanical properties of nanostructured ceria–zirconia fabricated via colloidal processing and slip casting process with cold isostatic pressing (CIP). Twenty-five pellet specimens were prepared from ceria–zirconia with 20 nm particle size. CeO2 nanopowder was mixed with Y-TZP nanopowder via colloidal processing. The consolidation of the powder was done via slip casting followed by CIP. The samples were divided into five different sintering temperatures with. Results from FESEM, density and hardness analyses demonstrated statistically significant increase in density and hardness as the sintering temperature increased. The hardness increased from 4.65 GPa to 14.14 GPa, and the density increased from 4.70 to 5.97 (g/cm3) as the sintering temperature increased without changing the holding time. Sintering Ce-Y-TZP at 1600 °C produced samples with homogenous structures, high hardness (14.14 GPa), and full densification with 98% of the theoretical density.

INFLUENCE OF PROCESSING ON MECHANICAL PROPERTIES OF 3Y-TZP FOR DENTAL APPLICATIONS

2016 ◽  
Vol 78 (11-3) ◽  
Author(s):  
Mohamed Aboras ◽  
Andanastuti Muchtar ◽  
Che Husna Azhari ◽  
Norziha Yahaya ◽  
Chin Chuin Hao
Keyword(s):  
Mechanical Properties ◽  
Phase Distribution ◽  
Slip Casting ◽  
Tetragonal Zirconia ◽  
Casting Process ◽  
Cold Isostatic Pressing ◽  
Colloidal Processing ◽  
X Ray Diffraction ◽  
Consolidation Process ◽  
Dental Applications

Purpose: This study aimed to investigate the influence of processing on the mechanical properties of 3 mol% yttrium–tetragonal zirconia (3Y–TZP) for dental applications. In this study, cold isostatic pressing (CIP) was adopted as a second consolidation process to enhance the mechanical properties of slip-cast 3Y–TZP. Methods: Two batches were prepared. The first batch of 3Y–TZP suspension was fabricated via colloidal processing. Then, the suspension was subjected to the slip casting process. Simultaneously, the second batch was prepared via colloidal processing, followed by CIP. The specimens were sintered at 1600 °C.  Sintered density, hardness, microstructure, and phase distribution were examined and analyzed. Results showed that the specimens fabricated via slip casting and CIP had the highest density of 99% of the theoretical density (6.1 g/cm3) and hardness of 14.4 GPa. The microstructure of the CIP samples was homogeneous with low porosity. According to X-ray diffraction examination, both batches exhibited a single phase (tetragonal phase). Conclusion(s): The density, hardness, and homogeneity of the microstructure of Y–TZP fabricated via slip casting and CIP improved. Using CIP as the second consolidation method improved the quality of green bodies

Mechanical Properties of ZTA Composite Using Cold Isostatic Pressing and Uniaxial Pressing

2013 ◽  
Vol 740 ◽  
pp. 728-733
Author(s):  
A.M. Mustafa Al Bakri ◽  
Mohd Noor Ahmad Fauzi ◽  
H. Kamarudin ◽  
M.N. Norazian ◽  
M.A.A. Salleh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Maximum Load ◽  
Cold Isostatic Pressing ◽  
Physical Interaction ◽  
Sintering Process ◽  
Transformation Toughening ◽  
Soaking Time ◽  
Isostatic Pressing ◽  
Different Temperatures ◽  
Properties Of Composites

Alumina-zirconia composite is an engineering material with a great potential to be develop for application as high temperature resistance structural material. In this research, zirconia toughness alumina (ZTA) was produced by physical interaction between Al2O3powder and Y2O3-ZrO2powder. Two composition of powder with different Al2O3: Y2O3-ZrO2ratio was used, 70:30 and 80:20 by weight. Two different compaction methods, i.e. uniaxial pressing and cold isostatic pressing (CIP) with a maximum load of 150 MPa were used in this research to investigate the differences in properties of composites. Sintering process was done at four different temperatures with the heating rate is 5 o C/ min with a soaking time of five hours. Mechanical testing, i.e. compressive strength and hardness was performed to all samples. The microstructure analysis using a Scanning Electron Microscope SEM was also studied. From the result, the composite with the ratio of 70:30 showed better mechanical properties as compared to 80:20 composite. Addition of zirconia in the composite gave an increased in toughness due to transformation toughening mechanism of tetragonal to monoclinic phase. As a conclusion the composites produced high compaction green density will improved the sintering process, resulting in improved mechanical properties.

IMPROVEMENT OF MECHANICAL PROPERTIES OF Y-TZP VIA CERIA ADDITION AND COLD ISOSTATIC PRESSING METHOD

2015 ◽  
Vol 77 (6) ◽  
Author(s):  
Mohamed Aboras ◽  
Andanastuti Muchtar ◽  
Che Husna Azhari ◽  
Norziha Yahaya ◽  
Chin Chuin Hao
Keyword(s):  
Mechanical Properties ◽  
Slip Casting ◽  
Tetragonal Zirconia ◽  
Xrd Analysis ◽  
Cold Isostatic Pressing ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Pressing Method ◽  
Isostatic Pressing ◽  
Lower Porosity

Fabrication and composition of tetragonal zirconia have been extensively studied to enhance its mechanical properties. The present study aims to investigate the mechanical properties of yttrium-stabilized zirconia (Y-TZP) with ceria addition consolidated via cold isostatic pressing (CIP). 3Y-TZP was prepared by slip casting. Another batch of samples was fabricated via slip casting with the addition of 5 wt% of ceria, followed by CIP. All samples were sintered at 1600 °C. Results showed that the density and hardness of Y-TZP increased with the addition of ceria and use of CIP. The density increased from 91.8% to 98% of theoretical density, and the hardness increased from 10.33 GPa to 14.14 GPa. Field-emission scanning electron microscopy (FESEM) images showed that Y-TZP with ceria and consolidated via CIP had more homogenous grain structure with lower porosity. The X-ray diffraction (XRD) analysis showed that the phase was 100% tetragonal for both materials. Ceria addition consolidated via CIP are an effective method to improve the mechanical properties of Y-TZP. 

CHARACTERIZATION OF HYDROXYAPATITE/TI6AL4V COMPOSITE POWDER UNDER VARIOUS SINTERING TEMPERATURE

2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif
Keyword(s):  
Mechanical Properties ◽  
Composite Powder ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Different Temperatures ◽  
Two Phases ◽  
Work Interaction

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 

Influences of the processing method and sintering temperature on the translucency of polycrystalline yttria-stabilized tetragonal zirconia for dental applications

2018 ◽  
Vol 44 (15) ◽  
pp. 18641-18649 ◽  
Author(s):  
Chuin Hao Chin ◽  
Andanastuti Muchtar ◽  
Che Husna Azhari ◽  
Masfueh Razali ◽  
Mohamed Aboras
Keyword(s):  
Sintering Temperature ◽  
Tetragonal Zirconia ◽  
Processing Method ◽  
Dental Applications

Effect of Cold Isostatic Pressing on the Mechanical Properties of WC-8Co Cemented Carbide for Friction Stir Welding Tool

2014 ◽  
Vol 563 ◽  
pp. 107-111
Author(s):  
Chen Zhang ◽  
Bing Liang Liang ◽  
Yun Long Ai ◽  
Chang Hong Liu
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Relative Density ◽  
Cold Isostatic Pressing ◽  
Cemented Carbide ◽  
Vacuum Sintering ◽  
Pressing Method ◽  
Isostatic Pressing ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties

WC-8Co cemented carbide specimens were prepared via vacuum sintering. The effects of cold isostatic pressing (CIP) on microstructure and mechanical properties were investigated. The results show that only WC and Co3W3C (γ-phase) were detected by XRD without any else phases, even though Co. Dense WC-8Co cemented carbide samples were obtained and relative density reached over 98%. The pressing method, instead of pressure, took an important role in the mechanical properties of WC-8Co cemented carbide. KIC and TRS of WC-8Co cemented carbide were improved at least 27% and 24%, respectively, by the use of CIP. WC-8Co cemented carbide with excellent mechanical properties (HRA>93.5, KIC>11MPa·m1/2, TRS>870MPa) was obtained by using CIP.

scholarly journals Sintering Behavior of a Six-Oxide Silicate Bioactive Glass for Scaffold Manufacturing

2020 ◽  
Vol 10 (22) ◽  
pp. 8279
Author(s):  
Elisa Fiume ◽  
Gianpaolo Serino ◽  
Cristina Bignardi ◽  
Enrica Verné ◽  
Francesco Baino
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Tissue Repair ◽  
Sintering Temperature ◽  
Thermal Analyses ◽  
Three Dimensional ◽  
Sintering Behavior ◽  
Porous Scaffolds ◽  
Bioactive Glasses ◽  
Different Temperatures

The intrinsic brittleness of bioactive glasses (BGs) is one of the main barriers to the widespread use of three-dimensional porous BG-derived bone grafts (scaffolds) in clinical practice. Among all the available strategies for improving the mechanical properties of BG-based scaffolds, strut densification upon sintering treatments at high temperatures represents a relatively easy approach, but its implementation might lead to undesired and poorly predictable decrease in porosity, mass transport properties and bioactivity resulting from densification and devitrification phenomena occurring in the material upon heating. The aim of the present work was to investigate the sinter-crystallization of a highly bioactive SiO2-P2O5-CaO–MgO–Na2O–K2O glass (47.5B composition) in reference to its suitability for the fabrication of bonelike foams. The thermal behavior of 47.5B glass particles was investigated upon sintering at different temperatures in the range of 600–850 °C by means of combined thermal analyses (differential thermal analysis (DTA) and hot-stage microscopy (HSM)). Then, XRD measurements were carried out to identify crystalline phases developed upon sintering. Finally, porous scaffolds were produced by a foam replica method in order to evaluate the effect of the sintering temperature on the mechanical properties under compression loading conditions. Assessing a relationship between mechanical properties and sintering temperature, or in other words between scaffold performance and fabrication process, is a key step towards the rationale design of optimized scaffolds for tissue repair.

scholarly journals The Influence of Co Additive on the Sintering, Mechanical Properties, Cytocompatibility, and Digital Light Processing Based Stereolithography of 3Y-TZP-5Al2O3 Ceramics

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2789 ◽  
Author(s):  
Margarita Goldberg ◽  
Tatiana Obolkina ◽  
Sergey Smirnov ◽  
Pavel Protsenko ◽  
Dmitriy Titov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Ceramic Powder ◽  
Tetragonal Zirconia ◽  
Specific Area ◽  
Precipitation Method ◽  
Temperature Phase ◽  
Sintered Ceramic ◽  
Digital Light Processing

Nanocrystalline 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP) ceramic powder containing 5 wt.% Al2O3 with 64 m2/g specific area was synthesized through precipitation method. Different amounts of Co (0–3 mol%) were introduced into synthesized powders, and ceramic materials were obtained by heat treatment in the air for 2 h at 1350–1550 °C. The influence of Co addition on the sintering temperature, phase composition, microstructure, mechanical and biomedical properties of the obtained composite materials, and on the resolution of the digital light processing (DLP) printed and sintered ceramic samples was investigated. The addition of a low amount of Co (0.33 mol%) allows us to decrease the sintering temperature, to improve the mechanical properties of ceramics, to preserve the nanoscale size of grains at 1350–1400 °C. The further increase of Co concentration resulted in the formation of both substitutional and interstitial sites in solid solution and appearance of CoAl2O4 confirmed by UV-visible spectroscopy, which stimulates grain growth. Due to the prevention of enlarging grains and to the formation of the dense microstructure in ceramic based on the tetragonal ZrO2 and Al2O3 with 0.33 mol% Co the bending strength of 720 ± 33 MPa was obtained after sintering at 1400 °C. The obtained materials demonstrated the absence of cytotoxicity and good cytocompatibility. The formation of blue CoAl2O4 allows us to improve the resolution of DLP based stereolithographic printed green bodies and sintered samples of the ceramics based on ZrO2-Al2O3. The developed materials and technology could be the basis for 3D manufacturing of bioceramic implants for medicine.

Effects of Micropores on Processing and Properties of Porous Irons

2017 ◽  
Vol 863 ◽  
pp. 26-32
Author(s):  
Ming Zhou Su ◽  
Hui Meng Wang ◽  
Chang Chen
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Corn Starch ◽  
Sintering Temperature ◽  
Starch Content ◽  
Volumetric Shrinkage ◽  
Small Particle Size ◽  
Compressive Properties ◽  
Different Temperatures ◽  
Powder Metallurgy Route

Porous irons with only micropores were produced through powder metallurgy route. Corn starch of small particle size (5-15μm) was utilized to regulate the densification of green compacts. The structural and mechanical properties of porous irons sintered at different temperatures were evaluated. The porosities increased with increasing the starch content, which reduced compressive strength and increased volumetric shrinkage. The compressive yield stress increased with increasing sintering temperature. It was also found that the effect of sintering temperature on the microstructure and compressive properties was more obvious when green compacts were less densified. Moreover, volumetric shrinkage of porous irons without adding starch remains in a quite low level for different sintering temperatures.

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