Effect of La2O3-Rich Glass Addition on Sintering of Zirconia Based Ceramics

2008 ◽  
Vol 587-588 ◽  
pp. 104-108
Author(s):  
Claudinei dos Santos ◽  
R.C. Souza ◽  
Maria Helena F.V. Fernandes ◽  
Nuno A.F. Almeida ◽  
Flávia A. Almeida ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
X Ray Diffraction ◽  
Indentation Method ◽  
Glass Addition ◽  
X Ray ◽  
Heating And Cooling ◽  
Mesh Screen ◽  
Cold Pressed

In this study, the influence of La-rich glass addition and sintering conditions on the densification and mechanical properties of 3 mol.%Y2O3-stabilized tetragonal zirconia polycrystals (3Y-TZP) ceramics were evaluated. High-purity tetragonal ZrO2 powder stabilized with 3 mol.% Y2O3 and La2O3-Rich glass were used as starting powders. Two compositions, ZrO2 containing 5 and 10 wt.% of a La2O3-rich glass were studied in this work. The starting powders were mixed/milled by planetary milling, dried at 90°C for 24 hours, sieved through a 60 mesh screen and uniaxially cold pressed under 80 MPa. The samples were sintered in air at 1200, 1300 and 1400°C for 60min, and at 1450°C for 120min, with heating and cooling rates of 10°C/min. Sintered samples were characterized by relative density, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The mechanical properties, hardness and fracture toughness, were obtained by Vickers indentation method. Dense sintered samples were obtained for all conditions. Samples sintered at 1300°C for 60 min presented the optimal mechanical properties with hardness of 1170 kgf.mm-2 and fracture toughness of 8.3 MPam1/2.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

Techniques of SrAl12O19 Platelets Formation in ZTA

2015 ◽  
Vol 788 ◽  
pp. 246-251
Author(s):  
Natalya Belousova ◽  
Sergey Veselov ◽  
Nina Cherkasova ◽  
Aleksey Lazarev ◽  
Ruslan Kuzmin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Ceramic Material ◽  
Ceramic Materials ◽  
Mechanical Tests ◽  
Initial Material ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Platelet Formation

A possibility of the SrAl12O19platelet formation in the Al2O3– ZrO2ceramic using SrCO3or Sr3Al2O6is evaluated. An impact of two techniques of platelet synthesis on mechanical properties of the material is investigated. Defects revealed in the sintered ceramic material are analyzed. Recommendations on the best method of the SrAl12O19phase formation in ceramic materials are given based on the structural and X-ray diffraction analyses as well as on mechanical tests. It is shown that an addition of 3 wt% SrAl12O19into the ZTA ceramic results in an increase in fracture toughness by up to 30 % in comparison with the initial material.

HAp/TiO2 nanocomposites: Influence of TiO2 on microstructure and mechanical properties

2019 ◽  
Vol 54 (6) ◽  
pp. 765-772 ◽  
Author(s):  
Ajay Kumar Vemulapalli ◽  
Rama Murty Raju Penmetsa ◽  
Ramanaiah Nallu ◽  
Rajesh Siriyala
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Flexural Strength ◽  
Bone Growth ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure And Mechanical Properties ◽  
Energy Ball

Hydroxyapatite is a very attractive material for artificial implants and human tissue restorations because they accelerate bone growth around the implant. The hydroxyapatite nanocomposites (HAp/TiO2) were produced by using high energy ball milling. X-ray diffraction studies revealed the formation of HAp and TiO2 composites. Cubic-like crystals with boundary morphologies were observed; it was also found that the grain size gradually increased with the increase in TiO2 content. It was found that the mechanical properties (hardness, Young's modulus, fracture toughness, flexural strength, and compression strength)of the composites significantly improved with the addition of TiO2, which was sintered at 1200℃. These properties were then also correlated with the microstructure of the composites. This paper investigates the effect of titania (TiO2 = 0, 5, 10, 15, 20, and 25 wt%) addition on the microstructure and mechanical properties of hydroxyapatite (Ca10(PO4)6(OH)2) nanocomposites.

Effect of Trace Strontium Addition on Microstructure and Room Temperature Fracture Toughness of Nb-12Si-22Ti Alloys

2016 ◽  
Vol 849 ◽  
pp. 603-608 ◽  
Author(s):  
Mei Ling Wu ◽  
Feng Wei Guo ◽  
Ming Li ◽  
Ya Fang Han
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Fracture ◽  
The Relationship ◽  
Scanning Electron

The effect of strontium (Sr) addition (0.2 at.%) on the microstructure and mechanical properties of Nb-12Si-22Ti alloys were studied. Microstructure of the alloys was observed by scanning electron microscope, and their phase compositions were analyzed with X-ray diffraction and Electro-Probe Microanalyzer. The room temperature fracture toughness was measured. The results indicated that the phases of Nbss and Nb3Si were presented in Nb-12Si-22Ti alloys. However, with the Al and Sr addition, the alloys were composed of Nbss and β-Nb5Si3. Compared with the Nb-12Si-22Ti alloys, the value of room temperature fracture toughness increased about 46% and 73% with the addition of Al and Sr alloy, respectively. The relationship between the microstructure and the mechanical properties was discussed.

Mechanical Properties of AlMgB14-xTiB2 Prepared by Field Activated and Pressure Assisted Synthesis

2013 ◽  
Vol 745-746 ◽  
pp. 652-656
Author(s):  
Yang Miao ◽  
Wen Liu ◽  
Lei Zhuang ◽  
Hui Ling Cheng ◽  
Qing Sen Meng
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Mechanical Alloying ◽  
Composite Ceramic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wear Tests ◽  
Scanning Electron

In this paper, Mechanical alloying (MA) and field activated and pressure assisted synthesis (FAPAS) were used for preparing the ultra-hard, super-abrasive AlMgB14-xTiB2 composite ceramic. The samples were fabricated at 1500 under a pressure of 60 MPa. The microstructures and compositions of samples were observed and determined by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD). It was indicated that addition of TiB2 was effective for increasing both quantities. A maximum Vichers hardness of 38.5GPa and a fracture toughness of 3.85MPam½ of AlMgB14 reinforced with 70 wt.% of TiB2 were achieved. Abrasion wear tests showed that adding TiB2 would improve the wearability obviously.

scholarly journals Ag+, Cu2+ and Zn2+ doped hydroxyapatite/tricalcium phosphate bioceramics: Influence of doping and sintering technique on mechanical properties

2018 ◽  
Vol 12 (3) ◽  
pp. 268-276 ◽  
Author(s):  
Zeljko Radovanovic ◽  
Ðordje Veljovic ◽  
Lidija Radovanovic ◽  
Ilmars Zalite ◽  
Eriks Palcevskis ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tricalcium Phosphate ◽  
Microwave Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydroxyapatite Ceramics ◽  
Average Grain Size ◽  
Conventional Sintering ◽  
Scanning Electron

Green hydroxyapatite ceramics were obtained by cold uniaxial and isostatic pressing of hydrothermally synthesized powders, pure hydroxyapatite and hydroxyapatite doped with Ag+, Cu2+ and Zn2+ ions. The ceramics were conventionally and microwave sintered and analyzed by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction analysis, and energy-dispersive X-ray spectroscopy. The effect of doping on the mechanical properties of the obtained hydroxyapatite/tricalcium phosphate ceramics was examined by comparing their average grain size, porosity and values of the hardness and fracture toughness. The results showed that doping with Cu2+ ions caused the lowest porosity of the ceramics and the highest values of hardness and fracture toughness. The ceramics obtained from hydroxyapatite doped with Ag+ and Zn2+ ions exhibited worse mechanical properties due to the higher porosity even in the case of microwave sintering, which provide denser ceramics than conventional sintering.

scholarly journals Effect of silver nanoparticless in the structure and mechanical properties of mullite/Ag cermets

2019 ◽  
Vol 51 (2) ◽  
pp. 175-187
Author(s):  
Gabriela Téllez-Arias ◽  
José Miranda-Hernández ◽  
Oscar Olea-Mejía ◽  
J. Lemus-Ruiz ◽  
Eduardo Terrés
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
X Ray Diffraction ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Different Temperatures ◽  
Confocal Scanning ◽  
Confocal Scanning Microscopy ◽  
Scanning Electron

The objective of this work was to study the influence of the addition of silver nanoparticles in the microstructure of mullite at two different temperatures of sintering (1500 and 1600?C), in order to decrease the porosity and increase the density as well better the hardness and fracture toughness. The microstructural characteristics were studied by scanning electron microscopy, confocal scanning microscopy and X-ray diffraction. Mullite/Ag cermets with homogenous microstructure were and a fracture toughness of 2.42 MP??m1/2.

Boron Nitride Doped Transparent Polycrystalline Silicon Nitride Ceramics

2010 ◽  
Vol 658 ◽  
pp. 428-431
Author(s):  
Bhupendra Joshi ◽  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Zheng Yi Fu ◽  
Koichi Niihara ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Polycrystalline Silicon ◽  
Sintering Aids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitride Ceramics ◽  
Xrd Techniques ◽  
Scanning Electron

The addition of h- BN to a polycrystalline Si3N4 was to increase the fracture toughness and other mechanical properties such as flexural strength and hardness of the material. The hot pressed samples were prepared from the mixture of α-Si3N4, AlN, MgO and h-BN. The composite contained from 0 to 2 wt.% BN powder with sintering aids (9% AlN + 3% MgO). The transparency, mechanical properties and microstructure of hot pressed polycrystalline Si3N4-BN composite materials were investigated by UV/VIS spectrophotometer, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The transparency decreased with increasing the content of h-BN into Si3N4.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

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