| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Engineering Ceramics: Microstructure-Property-Performance Relations and Applications
|
| Presentation Title |
Al2O3-WC Ceramic Composites with Extremely Improved Mechanical Strength by Interfacial Segregation of Dilute Dopants |
| Author(s) |
Tomohiro Nishi, Tomoko Hishida, Yusuke Katsu, Yasuyuki Okimura, Takeshi Mitsuoka, Katsuyuki Matsunaga |
| On-Site Speaker (Planned) |
Tomohiro Nishi |
| Abstract Scope |
Alumina (Al2O3)-matrix tungsten-carbide (WC) composites are expected for cutting-tool application for aerospace industries. It is experimentally found that a small amount of Zr addition is effective to significantly increase their mechanical properties. Atomic resolution scanning transmission electron microscopy (STEM) observations show that doped Zr atoms are preferentially located at interfaces between Al2O3 and WC grains, forming atomic segregation layers. Density functional theory (DFT) calculations indicate favorable thermodynamic stability of the interfacial Zr segregation due to structural transition at the interface. Moreover, theoretical works of separation demonstrate remarkable increase in interfacial strength through the interfacial structural transition, which strongly supports reinforcement of the interfaces by single-layer Zr segregation. The small amount of Zr atoms at the interface can play an essential role in strengthening the Al2O3-WC ceramic composites. |