About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Innovative Process Design and Processing for Advanced Structural Materials
|
| Presentation Title |
Atomic-scale Unique Interface Observation of η/Al in Al-Zn-Mg Alloy |
| Author(s) |
Hwangsun Kim, Howook Choi, Juhyun Oh, Ho Kwon, Eun Soo Park, Sungwoo Lee, Gun-Do Lee, Miyoung Kim, Heung Nam Han |
| On-Site Speaker (Planned) |
Hwangsun Kim |
| Abstract Scope |
Al-Zn-Mg alloys have been widely used in automobile and aerospace industry due to its lightweight property and high strength. The main strengthening mechanism of Al-Zn-Mg alloy is known as precipitation hardening. The precipitation sequence has been reported as follows: Super-saturated solid solution → GP zones → η’ phase → η phase. Among the 15 differently oriented η precipitates, η<sub>1</sub>, η<sub>2</sub>, and η<sub>4</sub> have the highest proportion and the rest except for these are known to exist less than 1%. In this study, η<sub>4</sub> precipitates, which is mainly precipitated when heterogeneous nucleation occurs, were observed in atomic scale and it was confirmed that it has a pseudo-periodic step-like interfacial structure with Mg and Zn segregation. We compared the interface energy of simulated flat interface and experimentally observed unique interface using ab-initio calculation. Consequently, the unique interface was energetically favored. |