| Title |
Microstructural Aspects on the Superplastcity of 7475 Al Alloy |
| Authors |
김기석(Ki S . Kim); 신동혁(Dong H . Shin); 금동화(Dong W . Kum); 맹선재(Sun C . Maeng) |
| Abstract |
The microstructural aspects of the superplastic behavior in 7475 Al alloy are investigated. After superplastic tests, several specimens revealed large zones free of dispersoid particles-occasionally as large as 5㎛ across. Typical micrograph depicting dispersoid-free zones (DFZ) after 100% tensile strain showed DFZ at grain boundaries lying primarily normal to the tensile stress direction. This result emphasizes the importance of diffusional flow in explaining superplastic deformation of the fine-grained 7475 A1 alloy especially at low elongations, The dissolution and growth processes of dispersoid occured at high elongations and these processes can be responsible for the formation of the dispersoid-free zone. |