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Comparison of two β-SiAlON ceramics prepared from synthetic and natural raw materials
Noaman, Maha S. M., Lences, Zoltan, Vitkovič, Martin, Gabrišová, Z. and Palou, Martin Comparison of two β-SiAlON ceramics prepared from synthetic and natural raw materials Acta Chimica Slovaca, Vol.2, No. 2, 2009, 3-13
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| Attached Files |
| Name |
Description |
MIMEType |
Size |
Downloads |
acs_0042.pdf
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acs_0042.pdf |
application/pdf |
1.66MB |
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| Author(s) |
Noaman, Maha S. M.
Lences, Zoltan
Vitkovič, Martin
Gabrišová, Z.
Palou, Martin
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| Title |
Comparison of two β-SiAlON ceramics prepared from synthetic and natural raw materials
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| Journal name |
Acta Chimica Slovaca
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| Publication date |
2009
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| Year available |
2009
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| Volume number |
2
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| Issue number |
2
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| ISSN |
1337-978X
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| Start page |
3
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| End page |
13
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| Total pages |
11
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| Place of publication |
Bratislava
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| Publisher |
Slovak Technical University
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| Collection year |
2009
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| Language |
english
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| Subject |
250000 Chemical Sciences
250200 Inorganic Chemistry
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| Abstract/Summary |
Two types of β-SiALON ceramics (denoted SiALON-S and SiAlON -N) were synthesized by carbothermal reduction and nitridation. The starting raw materials used were commercial synthetic powders (AlN, Al2O3 and Si3N4) for SiAlON-S and natural aluminosilicate raw materials (pyrophilite) for SiAlON-N. Sintering of materials has been achieved by hot- isostatical pressing procedure at 1730 °C using Y2O3 as a sintering additive. In this study XRD and SEM methods were used. XRD method showed that SiAlON-S is pure aluminum silicon nitride oxide, while sample from natural pyrophilite is composed of two aluminum silicon nitride oxides and corundum. Hardness and fracture toughness values were measured for all samples, the average values (means of 10 measurements) of SiAlON-S and SiAlON -N were HV = 12.28 GPa and 12.34 GPa, KIC = 4.11 MPa m1/2 and 3.77 MPa m1/2 respectively. A new testing method was used to assess the resistance of SiAlON samples to repeated thermal shocks. Samples with initiated cracks by Vickers’s indentor were cyclically heated to 1000°C and cooled to 500°C. Apart from phase composition, the source of raw materials has a little influence on the properties of ceramic samples. Therefore, pyrophilite could be a potential natural source to synthesize SiAlON ceramics.
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| Keyword(s) |
SiAlON ceramics
starting materials
hardness
fracture toughness
thermal shock resistance
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