β-SiAlON Bonded Corundum Material and Its Application as Sliding Gate Plate for Continuous Casting

2007 ◽  
Vol 280-283 ◽  
pp. 1683-1686 ◽  
Author(s):  
Bo Quan Zhu ◽  
Xiang Cheng Li ◽  
Cong Jin Jin ◽  
Zeya Li ◽  
Shou Xin Tian
Keyword(s):  
Mechanical Properties ◽  
Oxidation Process ◽  
Raw Materials ◽  
Protective Layer ◽  
Modulus Of Rupture ◽  
Crushing Strength ◽  
Good Oxidation Resistance ◽  
Cold Crushing Strength ◽  
Gate Plate ◽  
Z Value

β-sialon bonded corundum-based sliding gate plate was developed from raw materials of Al, metallic silicon and alumina through nitriding-reaction process. It was found that the effects of β-sialon content on the physical properties are significant and the mechanical properties of developed sliding gate plate are strongly related to the Z-value. The materials with Z value of 2 and 20wt% β-sialon, exhibit the highest hot modulus of rupture and cold crushing strength. It was also found that sialon bonded corundum-based material has good oxidation resistance because a protective layer is formed during oxidation process.

Investigation on Al-Cr2O3-Al2O3 Sliding Gate Performance

2012 ◽  
Vol 466-467 ◽  
pp. 242-245
Author(s):  
Jun Jie Zhang ◽  
Yong Li ◽  
Jin Bao Li ◽  
Yuan Gao ◽  
Gong Dong Ma
Keyword(s):  
Mechanical Properties ◽  
Chromium Oxide ◽  
Aluminum Powder ◽  
High Performance ◽  
Phenolic Resin ◽  
Oxide Powder ◽  
Modulus Of Rupture ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Different Content

High performance Al-Cr2O3-Al2O3 sliding gate are made from tabular corundum, white fused corundum, aluminum powder, and chromium oxide powder. Phenolic resin is used as binder. The properties of the Al-Cr2O3-Al2O3 sliding gates with the different content of chromium oxide(mass percent 3%,6%,9%,12%,15%) which are made from different processes (dried at 200°C in air, fired at 1300°Cin N2 and fired at 1450°C in CO), are researched respectively. The results show that in different processes, the samples which contain 6% chromium oxide powder have higher cold crushing strength and hot modulus of rupture. After fired in N2, the new phases Al8Cr5 (1327°C), AlN are formed, and after fired in CO, Al8Cr5, Al2OC and Cr3C2 are formed. These materials are contributed to improve the mechanical properties of samples. The samples fired in N2 have the best performance.

scholarly journals The Effects of Sintering Temperature and Agro Wastes on the Properties of Insulation Bricks

2020 ◽  
Vol 17 (2) ◽  
pp. 113-119
Author(s):  
H.E. Mgbemere ◽  
E.O. Obidiegwu ◽  
A.U. Ubong
Keyword(s):  
Rice Husk ◽  
Raw Materials ◽  
Synthesis Method ◽  
Linear Shrinkage ◽  
Absorption Capacity ◽  
Modulus Of Rupture ◽  
Composition Analysis ◽  
Cold Crushing Strength ◽  
Two Temperatures ◽  
Ball Clay

In this research, kaolin, ball clay, sawdust and rice husk were used to produce insulation bricks through the solid state synthesis method. Two temperatures, 1100oC and 1200oC were used to sinter the green samples. X-ray fluorescence, scanning electron microscopy, compressive strength tests etc. were used to analyse the properties of the produced bricks. Chemical composition analysis on the starting raw materials showed that SiO2 and Al2O3 were the major constituents while Fe2O3, Na2O, K2O and TiO2 were the minor constituents. As the amounts of kaolin used in preparing the samples decrease, the bulk density, modulus of rupture and cold crushing strength of the bricks decreases while the water absorption capacity, linear shrinkage increases. The thermal analysis showed that on heating the samples, the reactions were mainly exothermic with between 8 to 10 mW/mg of heat released. The morphology of the samples showed that the pores began to collapse when the amount of kaolin present is below 70 wt. %. Sintering the samples at 1100oC and 1200oC led to slightly different values in the results and is therefore very significant. Keywords: Insulation bricks, Kaolin, sawdust, rice husk, temperature effects

Effect of MgAl2O4 Micrpowder on Physical Properties of Corundum Castables

2014 ◽  
Vol 633 ◽  
pp. 348-351
Author(s):  
Yao Sheng Hu ◽  
Ping An Chen ◽  
Bo Quan Zhu ◽  
Zheng Ma ◽  
Xiang Cheng Li
Keyword(s):  
Growth Rate ◽  
Physical Properties ◽  
Room Temperature ◽  
Raw Materials ◽  
Linear Shrinkage ◽  
Modulus Of Rupture ◽  
Crushing Strength ◽  
Heat Treated ◽  
Dispersion Agent ◽  
Aluminate Cement

Corundum-based castables were prepared by using tabular corundum, micropowder of MgAl2O4spinel and calcium aluminate cement as raw materials, as well as the addition of dispersion agent and retarder. The effect of spinel contents on physical properties of the castables has been investigated. The results showed that as the samples were heat treated at 1100 °C and 1600 °C, the linear shrinkage rate decreased and the strength of rupture and crushing at room temperature increased with spinel content increasing, while apparent porosity and bulk density remained the same. The hot modulus of rupture increased from 12 MPa to 20MPa with 67% growth rate, and crushing strength after thermal shock increased from 80MPa to 105MPa with 32% growth rate. The increasing of high-temperature properties was attributed to the staggered distribution between MgAl2O4spinel and CA6.

scholarly journals VARIABILITY OF SOME MECHANICAL PROPERTIES OF SAN RAMON TALL VARIETY OF COCONUT

CORD ◽  
1994 ◽  
Vol 10 (01) ◽  
pp. 34
Author(s):  
R. N. Palomar
Keyword(s):  
Mechanical Properties ◽  
Natural Variation ◽  
Elastic Limit ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Average Moisture Content ◽  
Rupture Stress ◽  
Crushing Strength ◽  
The Core ◽  
Strength In Compression

The natural variation of some strength properties of about 80‑year old brown‑and green‑pigmented San Ramon variety of coconut was investigated. The properties were determined from tests on small clear specimens in the air dry condition with an average moisture content of 16.98%. The mechanical properties studied include modulus of rupture, stress at elastic limit and modulus of elasticity in static bending, maximum crushing strength in compression parallel to grain, stress at elastic limit and in compression perpendicular to grain, and shear parallel to grain.   The brown‑pigmented trees showed significantly higher values in all the mechanical properties than the green‑pigmented palms.   For the brown‑and green‑pigmented trees, the values of strength properties markedly decreased with increasing height levels and significantly increased radially from the core to the periphery of the stem.

scholarly journals Magnesia-zircon brick: Evolution of microstructure, properties and performance with increasing sintering temperature

2013 ◽  
Vol 45 (2) ◽  
pp. 181-188
Author(s):  
J. Gao ◽  
Z. Guo ◽  
L. Wang ◽  
W. Jiang
Keyword(s):  
Bulk Density ◽  
Microstructural Evolution ◽  
Creep Resistance ◽  
Sintering Temperature ◽  
Modulus Of Rupture ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
And Performance ◽  
Evolution Of Microstructure ◽  
Font Color

Depending on phase components and densification, Magnesia-Zircon brick varies in appearance from white to veined and then brown with increasing sintering temperature. Properties including bulk density, apparent porosity and hot modulus of rupture as well as performance embodied with creep resistance and refractoriness continue to improve with sustaining enhancement of sintering temperature. Exceptionally, cold crushing strength first increases then decreases with rising sintering temperature and a peak exists at 1550oC. Microstructural evolution suffers zircon decomposition companying by silica escape, forsterite formation, matrix solidification and zirconia coagulation, until a zirconia/forsterite composites belt tightly coating on magnesia aggregates. Excessive coagulation of zirconia caused by oversintering probably results in microcracks formation and defects enlargement thereby degrades cold crushing strength.<br><br><font color="red"><b> This article has been retracted. Link to the retraction <u><a href="http://dx.doi.org/10.2298/SOS1303387E">10.2298/SOS1303387E</a><u></b></font>

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