| Title |
Anisotropic Mechanical Properties in an 8090 Al - Li Alloy (1) ( Microstructure and Mechanical Properties ) |
| Authors |
손기선(Ki Sun Sohn); 이성학(Sung Hak Lee); 김낙준(Nack J . Kim); 이종권(Chong Kwon Lee) |
| Abstract |
The main objective of the present paper is to study on the structure and property relations of an 8090 Al-Li alloy. Particular emphasis has been placed on clarifying the origin of the anisotropy of mechanical properties which occurs along the short-transverse (S-T) direction. Although the application of stretching generally improved overall tensile properties of the 8090 plate due to the enhanced precipitation of S` phase, S-T oriented specimen in peak-aged condition showed an elongation ductility of only 1%, limiting the applicapability of the 8090 plate. For the S-T oriented specimen, examination of the fracture surfaces reveals clearly an intergranular fracture mode without any evidence of ductile fracture. Thus, fractorgaphic observation in the S-T oriented 8090 plate shows that the presence of coarse second phase particles at grain boundaries and the elongated shape of grain structure strongly influence fracture initiation process, thereby drastically reducing mechanical properties of the S-T oriented specimen. |