Effect of Al2O3 Addition on the Mechanical Properties of Biocompatible ZrO2-Al2O3 Composites

2006 ◽  
Vol 530-531 ◽  
pp. 575-580 ◽  
Author(s):  
Claudinei dos Santos ◽  
L.H.P. Teixeira ◽  
Kurt Strecker ◽  
Carlos Nelson Elias
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Relative Density ◽  
Room Temperature ◽  
Ceramic Composites ◽  
Linear Increase ◽  
Powder Mixtures ◽  
Al2o3 Ceramic ◽  
Sintering Conditions

In this work, the effects of alumina additions on the properties of the ZrO2-Al2O3 ceramic composites were investigated. Samples of ZrO2 with Al2O3 additions varying between 0 and 30wt-% were prepared. The powder mixtures were milled, compacted by uniaxial cold pressing and sintered at 16000C, in air, for 2 hours. The sintered samples were characterized by their relative density, phase composition and microstructure. As mechanical properties at room temperature, their Vickers hardness and fracture toughness were determined: In all sintering conditions and Al2O3 amounts, the samples presented relative density higher that 99%. The Al2O3 addition produces a linear increase of the hardness, reaching values between 1350 and 1610 HV for the addition of 0 and 30% of alumina, respectively. The fracture toughness was near to 8 MPam1/2 in all conditions. The phase composition, microstructure and relative density were correlated in order to interpret the mechanical properties obtained.

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.

scholarly journals Low-temperature degradation resistance and plastic deformation of ATZ ceramics stabilized by CaO

2021 ◽  
Vol 2103 (1) ◽  
pp. 012075
Author(s):  
AA Dmitrievskiy ◽  
DG Zhigacheva ◽  
VM Vasyukov ◽  
PN Ovchinnikov
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Phase Composition ◽  
Low Temperature ◽  
Uniaxial Compression ◽  
Calcium Oxide ◽  
Tetragonal Phase ◽  
Room Temperature

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.

Microstructure and Mechanical Properties of Hot-Pressed and Pressureless Sintered WC-Al2O3 Ceramic Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Hidehiro Endo ◽  
Masanori Ueki
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Composite System ◽  
Ceramic Composites ◽  
Pressureless Sintering ◽  
Sintering Aid ◽  
Al2o3 Ceramic ◽  
Remarkable Improvement

AbstractFully densified WC-A12O3 composites were successfully consolidated by both hot-pressing and pressureless sintering. The optimum hot-pressing condition for the composites was 1700°C for 2h under a pressure of 40MPa. A remarkable improvement in mechanical properties was achieved in the composite system, especially in WC-30 and -70vol%A12O3, compared to the monolithic WC and A12O3 ceramics. The addition of MgO as a sintering aid had a great effect on the properties of the composites. WC-30vol%A12O3 composite with 1.Owt% MgO addition exhibited flexural strength higher than 1000MPa up to 1200°C, fracture toughness; KIC≥7MPa√m, and hardness; HV ≥2450. In pressureless sintering with the addition of MgO as a sintering aid and subsequent HIP treatment, the WC-30vol%A12O3 composite exhibited the flexural strength higher than 900MPa up to 1200°C.

scholarly journals Структура и механические свойства композиционной керамики CaO-ZrO-=SUB=-2-=/SUB=--Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- при малых концентрациях корунда

2019 ◽  
Vol 89 (1) ◽  
pp. 107 ◽  
Author(s):  
А.А. Дмитриевский ◽  
А.О. Жигачев ◽  
Д.Г. Жигачева ◽  
А.И. Тюрин
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Coefficient Of Friction ◽  
Zirconium Dioxide ◽  
Friction And Wear ◽  
Ceramic Composites ◽  
Porosity Coefficient

AbstractWe have studied the effect of the ratio between concentrations of zirconium dioxide (stabilized by CaO) and corundum on phase composition and mechanical properties of nanostructured CaO–ZrO_2–Al_2O_3 ceramic composites. The CaO–ZrO_2–Al_2O_3 composites sintered at temperatures typical of ZrO_2 are found to be characterized by the optimal microhardness/fracture toughness ratio at corundum content $${{C}_{{{\text{A}}{{{\text{l}}}_{2}}{{{\text{O}}}_{3}}}}}$$ = 5%. These composites have a high flexural strength; their porosity, coefficient of friction, and wear are typical of those for CaO–ZrO_2 ceramics.

Synthesis and Properties of AlN-SiC-TiB2 Ceramics by SHS-HIP

2007 ◽  
Vol 353-358 ◽  
pp. 1517-1520 ◽  
Author(s):  
Li Juan Zhou ◽  
Yong Ting Zheng ◽  
Shan Yi Du
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Hot Isostatic Pressing ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Pressing Method ◽  
Maximum Value ◽  
High Temperature Synthesis

AlN-SiC-TiB2 ceramics were synthesized by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP) methods. The powder mixtures of Al, 6H-SiC and TiB2 were shaped by isostatic cool pressing method, and then combustion reaction was carried at the pressure of 100-200 MPa N2 by an ignitor. The solid solution of AlN and 2H-SiC in AlN-SiC-TiB2 ceramics was formed. The phase composition and microstructure were investigated by XRD and SEM. The mechanical properties of composite were measured as functions of composition. The maximum value of flexural strength and fracture toughness of composites were 430 MPa and 3.9 MPa⋅m1/2 respectively.

Characterization of Al2O3-Al2TiO2 Ceramic Composites: Effects of Sintering Parameters on the Properties

2018 ◽  
Vol 912 ◽  
pp. 118-123 ◽  
Author(s):  
Manuel Fellipe Rodrigues Pais Alves ◽  
Caio Marcelo Felbinger Azevedo Cossu ◽  
Roberto de Oliveira Magnago ◽  
Alfeu Saraiva Ramos ◽  
Claudinei dos Santos
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Ceramic Composites ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
Temperature Ranges ◽  
Distinct Temperature

This study aims to evaluate the effects of sintering parameters in crystalline phases, microstructure and mechanical properties of composites obtained through the Al2O3-TiO2 ceramic system. Cylindrical specimens, containing molar ratio of 3 Al2O3: 1 TiO2, were uniaxially pressed at 100 MPa. The applied sintering parameters were varied in five distinct temperature ranges (1300°C, 1400°C, 1500°C, 1575°C or 1600°C) for 2h and 1600°C for 10h. After sintering, samples were characterized by relative density, X-ray diffraction, scanning electron microscopy and mechanical properties (hardness and fracture toughness). After sintering the results point to a microstructure with grains near to 2.5mm, independent of the present phases and crystalline phases composed of: Al2O3 rhombohedral, TiO2 tetragonal e Al2TiO5 orthorhombic. The specimens sintered at 1600°C-10h feature densification 30% higher them the ones sintered at 1300°C-2h, reaching a density higher than 85% of theoretical density. The composite presents hardness higher than 1000HV and fracture toughness upper than 2.2MPam1/2. The better results for the mechanical properties were found in the composites sintered at 1600°C-10h, that showed a bigger relative density than all analyzed specimens, and only phases of Al2O3 and Al2TiO5 could be found, what means that all TiO2 was consumed in the sintering of the new composite.

Effect of B4C on the Mechanical Properties and Microstructure of ZrB2-SiC Based Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 218-221 ◽  
Author(s):  
Xuan Liu ◽  
Qiang Xu ◽  
Shi Zhen Zhu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Relative Density ◽  
Room Temperature ◽  
High Temperature Strength ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Room Temperature Strength

ZrB2-SiC-B4C is sintered at 1700°C by spark plasma sintering process. The effect of B4C content on the mechanical properties and microstructure of ZrB2-SiC based ceramics is studied. The results show that, with the content of B4C increases, the relative density and room-temperature strength decrease in the ZrB2-SiC-B4C composite. The fracture toughness rises at first and then falls down. The high temperature strength increases.

Effect of Sintering Pressure on Mechanical Properties of BN-Si3N4 Ceramic Composites Prepared by Spark Plasma Sintering

2016 ◽  
Vol 697 ◽  
pp. 188-192
Author(s):  
Jia Xin An ◽  
Wen Dong Xue ◽  
Feng Rui Zhai ◽  
Ruo Meng Xu ◽  
Jia Lin Sun
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Raw Materials ◽  
Ceramic Composites ◽  
Composite Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

BN-Si3N4 composite ceramic wave-transparent materials with excellent mechanical properties were prepared by spark plasma sintering (SPS) using h-BN and α-Si3N4 powders as raw materials, Al2O3 and Y2O3 as sintering aids. The influence of sintering pressure on density and mechanical properties of BN-Si3N4 composite ceramics were studied. The phases were observed by X-ray diffraction (XRD), and the microstructures were identified by scanning electron microscopy (SEM). The results showed that with the sintering pressure increases, the relative density, bending strength and fracture toughness of the composite ceramics were significantly increased, and the porosity decreased rapidly. The effects of pressure on the properties of the composite ceramics was not significant at >40MPa, so 40MPa is optimal for the composite ceramics to gain good overall performance, i.e. the relative density was 89.1%, the porosity was 2.3%, the bending strength reached 215.4 MPa, and the fracture toughness was 3.1/MPa·m1/2.

scholarly journals Mechanical properties and microstructure of Al2O3/TiAl in situ composites doped with Cr and V2O5

2012 ◽  
Vol 44 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Kun Zhang ◽  
Wang Fen ◽  
Jianfeng Zhu ◽  
Huae Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Flexural Strength ◽  
Strengthening Mechanism ◽  
Al2o3 Content ◽  
In Situ Composites ◽  
Al2o3 Ceramic ◽  
In Situ Composite

Al2O3/TiAl in situ composites doped with Cr and V2O5 were successfully prepared from Ti, Al, TiO2, Cr and V2O5 by hot pressing. The effect of in situ formed Al2O3 content on the phase composition, microstructure and mechanical properties of Al2O3/TiAl composites were investigated. The results show that the as-synthesized composites mainly consisted of ?-TiAl/?2-Ti3Al matrix and dispersive Al2O3 reinforcing phases. The in situ formed fine Al2O3 ceramic particles mainly disperse on the grain boundaries of TiAl, resulting in refinement of TiAl matrix, which improves the mechanical properties of the Al2O3/TiAl in situ composite. The composite with 7.54 at.% Al2O3 possesses the maximum flexural strength and fracture toughness of 335.38 MPa and 5.39 MPa m1/2, respectively. The strengthening mechanism was also discussed in detail.

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