Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7971816 | Materials Science and Engineering: A | 2018 | 24 Pages |
Abstract
In order to prepare high-performance and stable performance silicon nitride-based ceramic cutting tools, orthogonal experiment was carried out firstly to study the influence of sintering temperature and sintering aids (MgSiN2, Y2O3 and CeO2) on the densification and mechanical properties of the Si3N4 materials by spark plasma sintering. The results showed that Si3N4 ceramics with 5â¯wt%MgSiN2, 3â¯wt%Y2O3 and 1â¯wt%CeO2 sintering aids had the best relative density and mechanical properties at 1650â¯â. Secondly, the effects of sintering temperature on the densification, microstructure and mechanical properties of Si3N4 ceramics with 5â¯wt%MgSiN2, 3â¯wt%Y2O3 and 1â¯wt%CeO2 sintering aids were studied in detail. The results showed that the relative density of Si3N4 ceramics reached the maximum of 99.40â¯Â±â¯0.14% at 1650â¯â, the Vickers hardness and fracture toughness were 16.53â¯Â±â¯0.12â¯GPa and 6.89â¯Â±â¯0.20â¯MPaâ¯m1/2, respectively. The grain shapes were composed of equiaxed α-Si3N4 and long columnar β-Si3N4, and the transformation rate of α-Si3N4 to β-Si3N4 was 42.5%. Finally, the statistical distribution of the relative density, phase transformation rate and mechanical properties of Si3N4 ceramics with 5â¯wt%MgSiN2, 3â¯wt%Y2O3 and 1â¯wt%CeO2 sintering aids at 1650â¯â was investigated. It was found that the mechanical properties of silicon nitride ceramics sintered by spark plasma sintering were less dispersive, and the hardness and fracture toughness obeyed the two parameters Weibull distribution well.
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Physical Sciences and Engineering
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Materials Science (General)
Authors
Liyan Cao, Zhenhua Wang, Zengbin Yin, Kui Liu, Juntang Yuan,