Influence of Z Value and Sintering Temperature on Properties of β-Sialon Bonded Corundum Composite

2011 ◽  
Vol 287-290 ◽  
pp. 183-187 ◽  
Author(s):  
Yu Xiang Guo ◽  
Dian Li Qu ◽  
Yan Fen Sun ◽  
Sheng Xin Zhang

Using corundum particles and fine powder, α-Al2O3 powder, silicon powder, aluminum powder and some additives as raw materials, β-Sialon bonded corundum composite was synthesized in-situ at the nitrogen atmosphere. The influence of Z value in sialon phase and sintering temperature on physical properties, mechanical properties, thermal shock resistance and anti-oxidation performance of β-Sialon bonded corundum composite was investigated. The results indicate that the comprehensive properties of β-Sialon bonded corundum composite is excellent on condition that Z=2.75, sintering temperature is 1500°C at nitrogen atmosphere.

2012 ◽  
Vol 549 ◽  
pp. 691-694
Author(s):  
Fang Zhang ◽  
Zhi Liang Huang

The study is carried out combing with the production practice in Danjiangkou Hongyuan SiC limited. Si3N4 and SiC were prepared successfully from SiC and Silicon power in nitrogen atmosphere at 1425°C and 1375°C sintering temperature by the serial of techniques, such as ingredients, mixing, molding and drying, respectively. In the actual production, silicon powder content and sintering temperature will directly influence the products of the bending strength and thermal shock resistance. By measuring bending strength, porosities, bulk density, XRD and FESEM, the bending strength and thermal shock resistance of samples were studied mainly by changing sintering temperature and silicon powder content. The results show that bending strength and thermal shock resistance of sample which was added 16% Si powder is best. And bending strength and thermal shock resistance of sample of 1425°C sintering temperature is higher than that of 1375°C sintering temperature.


2014 ◽  
Vol 633 ◽  
pp. 53-56
Author(s):  
Chuan Jing Li ◽  
Yong Li ◽  
Hai Xia Qin ◽  
Jia Lin Sun ◽  
Jun Hong Chen ◽  
...  

Al-Si3N4-Al2O3composite was prepared using tabular corundum, white fused corundum,α-Al2O3fine powder and Si3N4fine powder as raw materials and phenolic resin as low temperature binder under nitrogen atmosphere at 1 300 °C for 8 h. The results show that the main reinforced phase of Al-Al2O3is Al4O4C in Al-Al2O3specimens without Si3N4fine powder adding,the main reinforced phase of Al-Si3N4-Al2O3is SIALON while small quantity of Al,Si plastic phase presents in Si3N4adding Al-Al2O3specimens. Si5AlON7(Z=1) is formed in Al-Si3N4-Al2O3specimens at low temperature (1 300 °C), which presents good comprehensive properties.


2016 ◽  
Vol 697 ◽  
pp. 591-594
Author(s):  
Shao Hua Wang ◽  
Cheng Ji Deng ◽  
Hong Xi Zhu ◽  
Wen Jie Yuan

The in situ nitrides bonded MgAl2O4-C refractories were prepared by using high quality fused spinel (MgAl2O4≥ 97%), natural flake graphite (C ≥ 96%) and silicon powder (Si ≥ 98%) as raw materials and the liquid calcium lignosulfonate with a concentration of 1.25 g/ml was used as binder (4 wt%). The effect of sintering temperatures on physical properties and phase compositions were investigated. The results show that β-sialon and α-Si3N4were formed in the samples sintered at 1400°C, 1450°C and 1500°C, and AlON and AlN were formed in the samples sintered at 1550°C. The sample that sintered at 1450°C exhibits the best bulk density and apparent porosity of 2.84 g/cm3 and 14.73%, respectively, and the highest compressive strength


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Kuai Zhang ◽  
Yungang Li ◽  
Hongyan Yan ◽  
Chuang Wang ◽  
Hui Li ◽  
...  

An Fe/FeAl2O4 composite was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method. The mass ratio was 6:1:2, sintering pressure was 30 MPa, and holding time was 120 min. The raw materials for the powder particles were respectively 1 µm (Fe), 0.5 µm (Fe2O3), and 1 µm (Al2O3) in diameter. The effect of sintering temperature on the microstructure and mechanical properties of Fe/FeAl2O4 composite was studied. The results showed that Fe/FeAl2O4 composite was formed by in situ reaction at 1300 °C–1500 °C. With the increased sintering temperature, the microstructure and mechanical properties of the Fe/FeAl2O4 composite showed a change law that initially became better and then became worse. The best microstructure and optimal mechanical properties were obtained at 1400 °C. At this temperature, the grain size of Fe and FeAl2O4 phases in Fe/FeAl2O4 composite was uniform, the relative density was 96.7%, and the Vickers hardness and bending strength were 1.88 GPa and 280.0 MPa, respectively. The wettability between Fe and FeAl2O4 was enhanced with increased sintering temperature. And then the densification process was accelerated. Finally, the microstructure and mechanical properties of the Fe/FeAl2O4 composite were improved.


2011 ◽  
Vol 284-286 ◽  
pp. 73-77
Author(s):  
Wen Wu Wang ◽  
Hui Yan Cao ◽  
Zhi Ping Zhang ◽  
Jing Xiang Wang

Based on SiC grains and powder, flake graphite, AlN powder, Silicon powder, sintered alumina ultra-fine powder as the starting materials, the sample of SiAlON-Graphite-SiC composites was prepared by firing under N2 atmosphere at 1 550°C and then analyzed in terms of high temperature performances by XRD, SEM and EDAX etc. The interrelation between composition, structure and performance of the material was also investigated. It indicates that this material provides excellent thermal shock resistance and molten alkali resistance, also proper oxidation resistance and applicable as the inner lining of the blast furnace.


2011 ◽  
Vol 399-401 ◽  
pp. 331-335 ◽  
Author(s):  
Jun Li ◽  
Wen Jie Yuan ◽  
Shuo Wang ◽  
Hong Xi Zhu ◽  
Cheng Ji Deng

Effect of sintering temperatures on reaction-bonded Si3N4/SiC composite ceramics under pressureless was investigated. Si3N4/SiC composite ceramics were sintered at different temperatures from 1450 to 1700 °C under nitrogen atmosphere by using SiC with different particle sizes, Si and additives Y2O3 as raw materials. The phases, microstructure and mechanical property were characterized by XRD, SEM, and compressive strength tests. The results demonstrated that when the particle gradation consists of silicon carbide of 74 μm (5 wt.%), 44 μm (10 wt.%) and 0.5 μm(35 wt.%) and silicon powder of 74 μm (42 wt.%), the more dense samples with the bulk density of 2.43 g/cm3 and the higher compressive strength of 324 MPa could be obtained at the sintering temperature of 1550 °C for 3h as the optimum processing parameters.


2007 ◽  
Vol 336-338 ◽  
pp. 1361-1363 ◽  
Author(s):  
Gang Bin Yang ◽  
Yin Juan Liu ◽  
Guan Jun Qiao ◽  
Zhi Hao Jin

The SiC/Si multilayer composites were fabricated successfully by reaction sintering method with normal stacked papers as the raw materials. Paper was cut into rectangular sheets and stacked, then infiltrated with phenolic resin to get a laminar structure. This paper /resin laminar composite was transformed into porous carbon with laminar structure after heating at 800 oC for 2h in N2 atmosphere. Finally this porous laminar carbon was reheated with silicon powder at 1450-1650oC for 1-2h in a vacuum furnace and SiC/Si multilayer composites can be obtained through the in-situ reaction between carbon and liquid silicon. The microstructure, reaction mechanism, phase composition and mechanical properties of these multilayer composites were researched. The final material shows a distingished laminar structure with alternating arrangement of SiC thick layers and silicon thin layers. SiC layer was composed by beta-SiC and a little of free silicon and carbon not reacted. The capillarity infiltration and in-situ reaction of liquid silicon act key roles in this process. Higher strength and non-catastrophic failure mode for this material were observed.


2011 ◽  
Vol 695 ◽  
pp. 227-230
Author(s):  
Liu Yi Xiang ◽  
Fen Wang ◽  
Jian Feng Zhu ◽  
Xiao Feng Wang

Al2O3/TiAl composites were successfully fabricated by hot-press-assisted exothermic dispersion method with powder mixtures of Ti, Al, TiO2and Cr2O3as raw materials. The effect of sintering temperature on the microstructures and mechanical properties of Al2O3/TiAl composites has been investigated. The results show that the Rockwell hardness and density of the composites increased with increasing sintering temperature. But the flexural strength and fracture toughness peaked at 825 MPa and 7.29 MPa·m1/2, respectively, when the sintering temperature reached to1300 °C.


2011 ◽  
Vol 239-242 ◽  
pp. 1243-1247
Author(s):  
Xiu Mei Feng ◽  
Xiao Qing Lian ◽  
Ming Xue Jiang ◽  
Yi Ner He

Al2O3-Ti(C,N)composite ceramics were prepared by in situ aluminothermic reduction and pressureless sintering. The effects of different Ti(C,N) contents and sintering temperatures on microstructure and mechanical properties (bulk density ,apparent porosity and blending strength)of samples were investigated through experiments.The results show that Al2O3-Ti(C,N) composite ceramics with 10 wt.% Ti(C,N) prepared using titanium dioxide and metal aluminum powder as raw materials and sintered at 1300 °C for 3h under a flowing nitrigen stream have good properties ,with bulk density 2.94g/cm3,apparent porosity 26.4%, and blending strength reaches to 28.04 MPa. According to the microstructure analysis,the fine in situ synthesis Ti(C,N) particles are uniformly dispersed in tabular alundum matrix. Ti(C,N) and tabular alundum phases are closely combined and can inhibit grain growth each other,which is benefical in improving the comprehensive properties of composite ceramics.


2011 ◽  
Vol 284-286 ◽  
pp. 335-338
Author(s):  
Jian Zhang ◽  
Jing Long Bu ◽  
Rong Lin Wang ◽  
Zhi Fa Wang

β-sialon-ZrO2composites with Si5AlON7 or Si4Al2O2N6 bonding phase were prapared in N2 atmosphere at 1550°C with Si, Al2O3, AlN and ZrO2 (Ca) as raw materials by reaction in situ pressureless sintering. Effect of Z value and content of β-sialon batch on its sintering performance, phase composition, microstructure, and thermal expansion character were investigated. Results showed that the phase of Si5AlON7 was formed in samples with β-sialon designing Z=1, and phases of Si5AlON7 and Si4Al2O2N6 were formed in samples with β-sialon designed Z=2 and β-sialon designed Z=3, respectively and Bending strength of samples increase with content of β-sialon batch. When content of β-sialon batch equals 10wt%, 15wt% and 15% respectively, the samples with β-sialon designed Z=1, Z=2, and Z=3 have lower apparent porosity, microstructure of homogeneous and compact and lower thermal expansion coefficient, respectively.


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