| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Engineering Ceramics: Microstructure-Property-Performance Relations and Applications
|
| Presentation Title |
Deviations from Hall-Petch Relationships in Nanocrystalline Ceramics |
| Author(s) |
Heonjune Ryou, Kevin Anderson, John Drazin, Edward Gorzkowski, Boris Feygelson, James Wollmershauser |
| On-Site Speaker (Planned) |
Heonjune Ryou |
| Abstract Scope |
Advancement in ceramic synthesis and manufacturing processes in recent years has enabled production of nanocrystalline ceramics with extremely small grain sizes: well below 100 nm. Many studies have reported the extent of the mechanical property improvement in nanocrystalline ceramics, which typically follows a conventional Hall-Petch relationship. However, there are cases when the hardness of nanocrystalline ceramics deviates from conventional Hall-Petch relationships. In this presentation, various nanocrystalline ceramics with grain sizes below 100 nm were characterized by instrumented indentation and two different types of deviation from conventional Hall-Petch relationships are observed in nanocrystalline ceramics. One type of deviation is a decrease in hardness below a certain grain size which suggests a change in strain accommodation mechanism at extremely small grain sizes. Another type of deviation is a shift in Hall-Petch line which suggests the superposition of multiple strengthening mechanisms. |