The Structure-Property-Processing Relationship for Sintered Yttria-Stabilized Zirconia (YSZ)/Alumina Bioceramics

2013 ◽  
Vol 25 (04) ◽  
pp. 1350005 ◽  
Author(s):  
Sea-Fue Wang ◽  
Thomas Chung-Kuang Yang ◽  
Ya-Ting Hsu ◽  
Sheng-Yang Lee ◽  
Jen-Chang Yang

The objective of this research is to study the effects of alumina addition on the microstructure-mechanical property relationship and sintering behavior of yttria (3 mol%)-stabilized zirconia (YSZ) ceramics. Well-dispersed YSZ / Al 2 O 3 ceramics containing 10–40 wt.% Al 2 O 3 were prepared by solid state reaction method. The relative density, average grain size, lattice parameters, microhardness, and fracture toughness of YSZ / Al 2 O 3 ceramics system sintered in the temperature range of 1250~1500°C as a function of Al 2 O 3 content were investigated. Experimental results showed that the ceramics with high Al 2 O 3 content and low sintering temperature tended to reveal low bulk densities. But the Al 2 O 3 content dependence on relative density for YSZ / Al 2 O 3 ceramics becomed deminishing when increasing the sintering temperature. Dense ceramics with composition of (80/20) ( YSZ / Al 2 O 3) and sintered at temperature of 1400°C and 1450°C revealed the optimal Vickers hardness and fracture toughness properties. These ceramics with high Al 2 O 3 content tended to reveal small grain sizes. The high sintering temperature governs the slow grain growth and high hardness in materials indicating the good correlation between microstructure of fabricated dense and mechanical properties.

2008 ◽  
Vol 368-372 ◽  
pp. 1764-1766 ◽  
Author(s):  
Yu Jin Wang ◽  
Lei Chen ◽  
Tai Quan Zhang ◽  
Yu Zhou

The ZrC-W composites with iron as sintering additive were fabricated by hot-press sintering. The densification, microstructure and mechanical properties of the composites were investigated. The incorporation of Fe beneficially promotes the densification of ZrC-W composites. The relative density of the composite sintered at 1900°C can attain 95.3%. W2C phase is also found in the ZrC-W composite sintered at 1700°C. The content of W2C decreases with the increase of sintering temperature. However, W2C phase is not identified in the composite sintered at 1900°C. The flexural strength and fracture toughness of the composites are strongly dependent on sintering temperature. The flexural strength and fracture toughness of ZrC-W composite sintered at optimized temperature of 1800°C are 438 MPa and 3.99 MPa·m1/2, respectively.


2010 ◽  
Vol 105-106 ◽  
pp. 720-722
Author(s):  
Hong Bo Li ◽  
Jun Ting Luo ◽  
Yong Fei Gu ◽  
Yan Xia Xu

Aluminum nitride (AlN) is a stoichiometric compound with the hexagonal wurtzite structure. AlN has excellent thermal conductivity and good properties as electronic insulator. It displays good mechanical resistance up to elevated temperatures and is resistant against corrosion by molten metals. Bulk AlN may therefore be used as a refractory structural material as well as a substrate for high power microelectronic devices. However, it is very difficult for sintering high-density AlN at lower temperature than 1800°C. Nano-sized AlN powders were sintered by hot press sintering at low temperature of 1500~1700°C and mechanical properties were investigated. β-AlN and β-Al2O3 were detected when the sintering temperature is 1600°C. The phase transition β-AlN to α-AlN was discovered at a 1700°C sintering temperature. Relative density and average grain size were increasing with the increasing of sintering temperature, and fracture form is intercrystalline crack in 1500°C and transcrystalline crack in 1700°C. 97.3% relative density and 850nm average grain size were deserved at 1700°C.


2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou

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.


2009 ◽  
Vol 23 (31n32) ◽  
pp. 3731-3737 ◽  
Author(s):  
JAE-SIK KIM ◽  
EUI-SUN CHOI ◽  
YOUNG-HIE LEE ◽  
KI-WON RYU

The sintering behavior and high frequency electro-magnetic properties of Ba3Co2Fe24O41ceramics were investigated for the small antenna application. All samples of the Ba3Co2Fe24O41ceramics were prepared by the solid-state reaction method and sintered at 1150°C 1400°C. From the XRD patterns of calcined Ba3Co2Fe24O41powders, the most suitable condition for calcining was 600°C–1000°C. Ba3Co2Fe24O41phase was observed in sintered Ba3Co2Fe24O41ceramics as main phase. Bulk densities increased with sintering temperature and decreased at 1400°C. Permittivity and permeability of the Ba3Co2Fe24O41ceramics increased or decreased with sintering temperature, respectively. On the other hand, loss tangent of permittivity and of permeability showed contrary tendency with permittivity and permeability. The permittivity and loss tangent of permittivity of Ba3Co2Fe24O41ceramics sintered at 1300°C were 19.896 and 0.171 at 210 MHz. and the measured value of permeability and loss tangent of permeability were 14.218 and 0.204, respectively.


2014 ◽  
Vol 616 ◽  
pp. 194-198 ◽  
Author(s):  
Jian Feng Zhang ◽  
Rong Tu ◽  
Takashi Goto

WC-Co-cBN composites were consolidated by SPS at 1373 to 1673 K under a moderate pressure of 100 MPa. The addition of cBN increased the starting and finishing temperature of shrinkage and decreased the relative density of WC-Co. The relative density of WC-(10-20 vol%) cBN composites was about 97-100% at 1573 K and decreased with increasing the sintering temperature to 1673 K due to the phase transformation of cBN to hBN. The highest hardness and fracture toughness of WC-Co-20 vol% cBN composite sintered at 1573 K were 23.2 GPa and 8.0 MP m1/2, respectively.


2013 ◽  
Vol 22 ◽  
pp. 501-510 ◽  
Author(s):  
S. K. TAK ◽  
M. S. SHEKHWAT ◽  
R. MANGAL

ZnO powder was synthesized by solid state reaction method. The synthesized powder was granulated and pressed using uni-axial press for preparing the pallets. The prepared pellets were sintered in conventional furnace at different temperatures (900-1300° C). The phase study was done by powder X-ray diffraction and it was found that the there is no other phase present in the synthesized material but the peak intensity is increasing with temperature. The crystallite size of the synthesized ZnO powder was found to be increase with temperature. The effect of sintering on grain growth is investigated by scanning electron microscopy (SEM). SEM revels that the average grain size is increases with increase in sintering temperature. AC impedance of these samples was decreased markedly with increased sintering temperature. In present work the effect of sintering temperatures and hold time on micro structural and electrical properties of ZnO ceramics is carried out.


2012 ◽  
Vol 584 ◽  
pp. 239-242
Author(s):  
C. Seshendra Reddy ◽  
A. Sivasankar Reddy ◽  
P. Sreedhara Reddy

La0.67Ba0.33MnO3 powders were successfully prepared by a standard solid state reaction method, and systematically investigated the influence of the sintering temperature on the structural, microstructure, composition properties. The XRD pattern showed that the as prepared LBMO material was in single-phase with rhombohedral structure. From the scanning electron micrographs, it was observed that the grain size increased with sintering temperature and the average grain size was ~40nm.The surface roughness was measured by atomic force microscope and the RMS roughness of samples was in the range 48 to 85 nm. The as prepared samples exhibited nearly the same composition of the base material.


2010 ◽  
Vol 434-435 ◽  
pp. 224-227
Author(s):  
Xu Ping Lin ◽  
Jing Tao Ma ◽  
Bao Qing Zhang ◽  
Ji Zhou

The influence of CuO-V2O5-Bi2O3 addition on the sintering behavior, phase composition, microstructure and microwave dielectric properties of Zn3Nb2O8 ceramics were investigated. The co- doping of CuO, V2O5 and Bi2O3 can significantly lower the sintering temperature of Zn3Nb2O8 ceramics from 1150°C to 900°C. The Zn3Nb2O8-0.5wt% CuO-0.5wt% V2O5-2.0wt% Bi2O3 ceramic sintered at 900°C showed a relative density of 97.1%, a dielectric constant (εr) of 18.2, and a quality factor (Q×f) of 36781 GHz. The dielectric properties in this system exhibited a significant dependence on the relative density, content of additives and sintering temperature. The relative density and dielectric constant (εr) of Zn3Nb2O8 ceramics increased with increasing CuO-V2O5-Bi2O3 additions. And also the relative density and dielectric constant of Zn3Nb2O8 ceramics increased by the augment of the sintering temperature.


2006 ◽  
Vol 114 ◽  
pp. 245-250
Author(s):  
Andrzej Michalski ◽  
D. Siemiaszko ◽  
Jakub Jaroszewicz ◽  
Marcin Rosiński ◽  
M. Psoda

Nanocrystalline WC-12wt.%Co was consolidated by Pulse Plasma Sintering (PPS) at various temperatures between 900 and 1200oC for 6 minutes under a pressure of 60MPa. Cemented carbides sintered at 1100oC have a relative density of 99%, a hardness of 2248HV30, the fracture toughness, KIC=12.5 MPa*m1/2, and have a structure containing 50nm WC crystallites. Increasing the sintering temperature to 1200oC causes an increase in the size of the WC crystallite size to about 110 nm, reduces the hardness to 2198HV30, and decreases the KIC to 9.7 MPa*m1/2.


2011 ◽  
Vol 01 (04) ◽  
pp. 379-382 ◽  
Author(s):  
DI ZHOU ◽  
LI-XIA PANG ◽  
JING GUO ◽  
YING WU ◽  
GAO-QUN ZHANG ◽  
...  

In the present work, a novel low temperature firing Bi 3 FeMo 2 O 12 ceramic was synthesized via the solid-state reaction method. The monoclinic Bi 3 FeMo 2 O 12 phase can be formed at a low temperature 670°C. A relative density above 96% can be obtained when sintering temperature is above 800°C. The Bi 3 FeMo 2 O 12 ceramic sintered at 845°C for 2 h shows high microwave dielectric performance with a permittivity ~27.2, a Qf value of 14,500 GHz and a temperature coefficient of -80 ppm/°C. It might be a candidate for low temperature co-fired ceramics technology.


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