Effect of grain growth in bimodal microstructure on cutting performance of self-toughening Dy-α-SiAlON ceramic tool inserts
| Autor: | Gao Beichen, Abulaiti Weinila, Guan Zheng, Liu Limeng |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Processing and Application of Ceramics, Vol 17, Iss 3, Pp 321-332 (2023) |
| Druh dokumentu: | article |
| ISSN: | 1820-6131 2406-1034 |
| DOI: | 10.2298/PAC2303321G |
| Popis: | Although significant increase in mechanical properties has been achieved in α-SiAlON ceramics by introducing self-toughening bimodal microstructure, the bimodal microstructure may not always result in better cutting performance of α-SiAlON tool inserts. Herein Dy-α-SiAlON ceramics were prepared by hot-pressing at 1900°C under 30MPa. Diameter and aspect ratio of the large elongated α-SiAlON grains pivotal to formation of bimodal microstructures were regulated by using 0-5wt.% Dy2O3 as a sintering additive. Mechanical properties and cutting performance of α-SiAlON tool inserts were evaluated. The results showed good Vickers hardness (19.0-19.7GPa) and fracture toughness (3.61-4.18MPa•m1/2) increasing with crack propagation length. However, transverse section of the large elongated grains was revealed as critical crack to cause premature fracture of the α-SiAlON ceramics. Fracture rather than attrition wear was recognized as dominant mechanism for tool failure, indicating that for better cutting performance of the α-SiAlON tool inserts a selftoughening microstructure consisting of thinner grains with large aspect ratio is required. |
| Databáze: | Directory of Open Access Journals |
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