Effect of additive composition on mechanical properties of pressureless sintered silicon carbide ceramics sintered with alumina, aluminum nitride and yttria
| Autor: | Yu-Kwang Seo, Jung-Hye Eom, Seoung-Jae Lee, Young-Wook Kim |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Metallurgy Metals and Alloys Sintering Nitride Condensed Matter Physics Microstructure chemistry.chemical_compound Fracture toughness chemistry Flexural strength Mechanics of Materials visual_art Materials Chemistry Silicon carbide visual_art.visual_art_medium Ceramic Yttria-stabilized zirconia |
| Zdroj: | Metals and Materials International. 21:525-530 |
| ISSN: | 2005-4149 1598-9623 |
| DOI: | 10.1007/s12540-015-4383-0 |
| Popis: | Silicon carbide (SiC) ceramics were pressureless sintered with 3 vol% Al2O3-Y2O3-AlN additives with the AlN/(Al2O3+AlN) molar ratios of 0-0.75 at 1850-2000 °C for 1 hr and the effects of additive composition (i.e., changes in the AlN/(Al2O3+AlN) molar ratio while maintaining constant Y2O3 content) on the mechanical properties of the pressureless-sintered SiC ceramics were investigated. Self-reinforced microstructures consisting of relatively large platelet SiC grains and relatively small equiaxed grains have been obtained in all specimens when sintered at 1900 °C for 1 h in an argon atmosphere. The achievement of self-reinforced microstructures under such mild conditions (holding for 1 hr at 1900 °C) is caused by the beneficial effects of additive composition and the acceleration of the β→α phase transformation of SiC by seeding, i.e., the addition of 1 vol% α-SiC into β-SiC. The typical flexural strength and fracture toughness of the pressureless-sintered SiC ceramics with an AlN/(Al2O3+AlN) mole ratio of 0.5 were 433 MPa and 6.6 MPa·m1/2 at room temperature, respectively. |
| Databáze: | OpenAIRE |
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