Fabrication and Oxidation-Resistance Property of Coated ZrB2-YAG-Al2O3 Multi-Phase Ceramics

2013 ◽  
Vol 544 ◽  
pp. 347-350
Author(s):  
Jie Guang Song ◽  
Fang Wang ◽  
Ming Han Xu ◽  
Shi Bin Li ◽  
Gang Chang Ji
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Protective Layer ◽  
Zirconium Diboride ◽  
Oxidation Temperature ◽  
Al2o3 Content ◽  
Precipitation Method ◽  
Composite Powders ◽  
Co Precipitation ◽  
Multi Phase

Zirconium diboride is widely applied because of some excellent performances. The results show the A1(OH)3-Y(OH)3/ZrB2 composite powders is prepared by a co-precipitation method, the shell-core structure A12O3-Y2O3/ZrB2 composite powders is prepared by sintering A1(OH)3-Y(OH)3/ZrB2 composite powders. The coating and density ZrB2-YAG-Al2O3 multi-phase ceramics is sintered at 1700°C, 20MPa for 4min by using Al2O3-Y2O3-80wt%ZrB2 composite powders, the oxidation weight is increased with increasing the oxidation temperature, however, the oxidation weight is decreased with increasing the YAG-Al2O3 content. ZrB2 reacted with O2 to form B2O3, and B2O3 is reacted with Al2O3 to form Al18B4O33, which is melted and coated on the surface of ceramics to form a protective layer for the oxidation resistance of ceramics at high temperature.

Influence of Coated Composite Powders on the Properties of ZrB2-YAG-Al2O3 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 451-456
Author(s):  
Jie Guang Song ◽  
Xiu Qin Wang ◽  
Fang Wang ◽  
Shi Bin Li ◽  
Gang Chang Ji
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Composite Powder ◽  
Raw Materials ◽  
Protective Layer ◽  
Ceramic Materials ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Spark Plasma

ZrB2, YAG and Al2O3 are widely applied because of some excellent performances, but ZrB2 is easily oxidized in the high-temperature air. To make the ZrB2 ceramics obtain better oxidation resistance, high-density ZrB2-YAG-Al2O3 ceramics were prepared. The influences of coated composite powders on the densification and the oxidation resistance of ZrB2-YAG-Al2O3 ceramics were investigated. The 80wt%ZrB2-YAG-Al2O3 multiphase ceramic materials from different composite raw materials with the spark plasma sintering technique were successfully prepared. The densification of ZrB2-YAG-Al2O3 ceramics with Al2O3-Y2O3 composite powder coated is easier than that of ZrB2-YAG-Al2O3 ceramics with YAG-Al2O3 powder mixed. The reaction temperature is lower than the 1100¡æ for synthesizing YAG powders from Al2O3-Y2O3 composite powders. The weight gain are increased with increased the oxidation temperature. B2O3 is reacted with Al2O3 to form Al18B4O33, Al18B4O33 is melted and coated on the surface of ceramics to form a protective layer for the oxidation resistance of ceramics at high temperature. The oxidation weight gain of ZrB2-YAG-Al2O3 ceramic with Al2O3-Y2O3 composite powder coated is lower than that of ZrB2-YAG-Al2O3 ceramic with YAG-Al2O3 powder mixed.

Effect of Auxiliary on the Dispersibility of ZrB2 Powder in the Liquid

2017 ◽  
Vol 893 ◽  
pp. 105-109
Author(s):  
Jie Guang Song ◽  
Xiu Qin Wang ◽  
Long Tao Liu ◽  
Zhi Hui Li ◽  
Ru Xin Deng ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Spark Plasma Sintering ◽  
Composite Powder ◽  
Precipitation Method ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Co Precipitation

The composite ZrB2 powder coated A12O3-Y2O3 prepared by co-precipitation method were densified via the spark plasma sintering (SPS) and then researched the oxidation resistance at high temperature. ZrB2 powder must have the better dispersibility during the coating processing for obtaining the better coating effect. Effect of dispersant on the dispersibility of ZrB2 powder in the liquid is researched in this paper, the results show ZrB2 powder have the better dispersibility as the dispersant for PMAA and the content for 2vol%, which lay foundation for synthsising the better coating effect coated A12O3-Y2O3-ZrB2 composite powder.

Sintering Character of Coated Al2O3-Y2O3/ZrB2 Composite Powder Materials via Spark Plasma Sintering

2013 ◽  
Vol 804 ◽  
pp. 42-46
Author(s):  
Jie Guang Song ◽  
Ming Han Xu ◽  
Xiu Qin Wang ◽  
Shi Bin Li ◽  
Gang Chang Ji
Keyword(s):  
High Temperature ◽  
Spark Plasma Sintering ◽  
Composite Powder ◽  
Raw Materials ◽  
Powder Materials ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Co Precipitation ◽  
Multi Phase

ZrB2 has some excellent physical performance and chemical stability, it has been widely applied in a lot of fields. In order to improve disadvantages of ZrB2 that the sintering densification of ZrB2 is too difficult, and it is easy oxidized at high temperature, in this paper, the sintering character of coated A12O3-Y2O3/ZrB2 composite powder materials via spark plasma sintering were investigated. Al2O3-Y2O3/ZrB2 composite powders were prepared by a co-precipitation methods. When the pH is 9, the encapsulted structure of A1(OH)3-Y(OH)3/ZrB2 composite powders is the best. By analyzing the ZrB2 surface status with TEM, the A12O3-Y2O3/ZrB2 composite powders were prepared under the calcining conditions of 600°C¡æ in argon. The high density ZrB2-YAG multi-phase ceramics are prepared via spark splama sintering, which indicate the raw materials adding A12O3-Y2O3 help for the densification of ZrB2 ceramics.

Synthesis Mechanism of ZrB2@A12O3-Y2O3 Composite Powders with Core-Shell Microstructure

2016 ◽  
Vol 680 ◽  
pp. 133-136 ◽  
Author(s):  
Jie Guang Song ◽  
Da Ming Du ◽  
Fang Wang ◽  
Ming Han Xu ◽  
Shi Bin Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Sintering Temperature ◽  
Precipitation Method ◽  
Core Shell ◽  
High Temperature Strength ◽  
Shell Microstructure ◽  
Composite Powders ◽  
Synthesis Mechanism ◽  
Co Precipitation ◽  
Shell Composite

ZrB2 has some excellent high-temperature performance. However, due to it is easily oxidized in the high-temperature air to impact high-temperature strength, which restricts its applied range. To decrease the oxidization and sintering temperature, and improve the strength of ZrB2 at high temperature, in this paper, the prepared composite powders is analyzed with XRD, SEM, EDS and TEM, which proves ZrB2@A12O3-Y2O3 core-shell composite powders are successfully synthesized by co-precipitation method, the synthesis mechanism of ZrB2@A12O3-Y2O3 core-shell composite powders is received through the results discussion.

Synthesis of the high temperature superconductor YBa2Cu3O7−δ by the hydroxide co-precipitation method

1997 ◽  
Vol 278 (1-2) ◽  
pp. 55-61 ◽  
Author(s):  
I. Schildermans ◽  
M. Van Bael ◽  
E. Knaepen ◽  
J. Yperman ◽  
J. Mullens ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Superconductor ◽  
Precipitation Method ◽  
Co Precipitation

Oxidation Behavior of Tantalum Boride Ceramics

2007 ◽  
Vol 124-126 ◽  
pp. 819-822 ◽  
Author(s):  
Junichi Matsushita ◽  
Geum Chan Hwang ◽  
Kwang Bo Shim
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Surface Film ◽  
Oxidation Time ◽  
Oxidation Temperature ◽  
Weight Changes ◽  
Good Oxidation Resistance ◽  
Resistant Layer

The oxidation behavior of tantalum diboride (TaB2) powder at high temperature was investigated in order to determine the possibility of the use of advanced high temperature structural materials. Unfortunately, monolithic TaB2 were known to be chemical stability up to high temperatures. To date, there have been few reports regarding the properties of TaB2 ceramics. The samples were oxidized at room temperature to 1273 K for 5 minutes to 25 hours in air. The weight changes were measured to estimate the oxidation resistance. The oxidation of samples oxidized for short oxidation time of 5 minutes started at 873 K, and the weight gain increased with increasing oxidation temperature. On the other hand, at the oxidation time of above 1 hour, a maximum weight gain value at 973 to 1073 K was observed. However, even if the oxidation temperature was increased an additional weight change slightly occurred. The weight gain of the sample oxidized at 1273 K for 5 minutes to 25 hours was about 40 to 20 % of the theoretical oxidation mass change. According to the powder X-ray diffraction date, the oxidized TaB2 sample was changed to Ta2O5 at 873 K. Finally, the TaB2 showed a good oxidation resistance at high temperature, because the surface film of tantalum oxide (Ta2O5) formed by oxidation acted as an oxidation resistant layer.

INFLUENCE OF SYNTHESIS CONDITIONS ON Al(OH)3–Y(OH)3/ZrB2 COMPOSITE PARTICLES

2007 ◽  
Vol 14 (06) ◽  
pp. 1135-1141 ◽  
Author(s):  
JIE-GUANG SONG ◽  
LIAN-MENG ZHANG ◽  
JUN-GUO LI ◽  
JIAN-RONG SONG
Keyword(s):  
High Temperature ◽  
Reaction Time ◽  
Precipitation Method ◽  
Composite Particles ◽  
Coating Quality ◽  
Ultrasonic Dispersion ◽  
High Temperature Properties ◽  
Synthesis Conditions ◽  
Solution Reaction ◽  
Co Precipitation

Although Zirconium diboride ( ZrB 2) is a desirable combination with some good properties, it is easily oxidized in the high-temperature air to impact high-temperature properties, which dwindles the applied range. In order to decrease oxidization and improve the high-temperature properties of ZrB 2, the surface of ZrB 2 is coated with Al ( OH )3– Y ( OH )3 to synthesize Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles. In this paper, the conditions of synthesizing Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles by the co-precipitation method are investigated. Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles are synthesized under different conditions, but the conditions of synthesizing Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles with the better coating quality require pH = 9, the appropriate concentration ( Al 3+ = 0.017 mol/L , Y 3+ = 0.01 mol/L ) of composite solution, reaction time of 60 min, titration speed of 0.05 ml/s, using the dispersant in the ZrB 2 suspension and the ultrasonic dispersion, respectively.

THERMODYNAMIC AND KINETIC ANALYSES OF SYNTHESIZING ZrB2@Al(OH)3–Y(OH)3 CORE–SHELL COMPOSITE PARTICLES

2007 ◽  
Vol 14 (01) ◽  
pp. 117-122 ◽  
Author(s):  
JIEGUANG SONG ◽  
LIANMENG ZHANG ◽  
JUNGUO LI ◽  
JIANRONG SONG
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Solubility Product ◽  
Ceramic Materials ◽  
Precipitation Method ◽  
Composite Particles ◽  
Core Shell ◽  
High Temperature Strength ◽  
Co Precipitation ◽  
Shell Composite

ZrB 2 has some excellent performances, but it is easily oxidized at high temperatures to impact the high-temperature strength, which restricts its applied range. To protect from the oxidization and improve the strength of ZrB 2 at high temperature, the surface of ZrB 2 particles is coated with the Al ( OH )3– Y ( OH )3 shell to synthesize ZrB 2@ Al ( OH )3– Y ( OH )3 core–shell composite particles. Through the thermodynamic and kinetic analyses of the heterogeneous nucleation and homogeneous nucleation, the concentration product of precursor ion ( Y 3+ or Al 3+) and OH - (Qi) must be greater than the solubility product (K sp ), respectively; the conditions of Y 3+ and Al 3+ are reached to produce Al ( OH )3– Y ( OH )3 shell on the ZrB 2 surface between the Y 3+ line and the AlO 2- line. Through TEM and XRD analyses, ZrB 2@ Al ( OH )3– Y ( OH )3 core–shell composite particles are successfully synthesized by the co-precipitation method, the shell layer quality is better at pH = 9, which established the foundation for preparing high-performance YAG / ZrB 2 and Al 2 O 3– YAG / ZrB 2 multiphase ceramic materials.

Enhancing the catalytic performance of cobalt oxide by doping on ceria in the high temperature water–gas shift reaction

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103023-103029 ◽  
Author(s):  
Ajay Jha ◽  
Dae-Woon Jeong ◽  
Yeol-Lim Lee ◽  
In Wook Nah ◽  
Hyun-Seog Roh
Keyword(s):  
High Temperature ◽  
Catalytic Performance ◽  
Water Gas Shift ◽  
Precipitation Method ◽  
High Temperature Water ◽  
Wgs Reaction ◽  
Co Precipitation ◽  
Shift Reaction ◽  
Water Gas ◽  
Temperature Water

The high temperature water–gas shift (HT-WGS) reaction was performed using a Co–CeO2 catalyst, prepared through a co-precipitation method.

EFFECT OF COATING CONTENT ON THE PROPERTIES OF A1(OH)3–Y(OH)3/ZrB2 COMPOSITE PARTICLES

2007 ◽  
Vol 14 (03) ◽  
pp. 445-449 ◽  
Author(s):  
JIE-GUANG SONG ◽  
LIAN-MENG ZHANG ◽  
JUN-GUO LI ◽  
JIAN-RONG SONG
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Oxidation Resistance ◽  
Zirconium Diboride ◽  
Resistance Ratio ◽  
Composite Particles ◽  
High Temperature Materials

Zirconium diboride is widely applied to high-temperature materials, but it is easily oxidized at high temperature. To increase the oxidation resistance of zirconium diboride at high temperature, the A 1( OH )3– Y ( OH )3 is coated on the ZrB 2 surface to prepare A 1( OH )3– Y ( OH )3/ ZrB 2 composite particles. In this paper, the effect of coating content on the properties of A 1( OH )3– Y ( OH )3/ ZrB 2 composite particles is investigated. It is analyzed that the particle size and particle size distribution of A 1( OH )3– Y ( OH )3/ ZrB 2 composite particles is increased with the coating content. The dispersion of ZrB 2 particles is largely increased with the coating content of 0%–20%; the dispersion of ZrB 2 particles is similar when the coating content is from 20% to 30%. The oxidation resistance ratio of the ZrB 2 particles with 30% coating content is the best than that of other conditions—it is about three times more than that of the original ZrB 2 particles.

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