| Title |
Effect on Tensile Properties by Primary αPhase in Bimodal Structured Ti - 6Al - 4V |
| Authors |
김두현(Doo Hyun Kim); 이용태(Yong Tai Lee) |
| Abstract |
Tensile property variation due co the modification of the volume fraction and average size of primary a in the bimodal structured Ti-6Al-4V has been studied. For the modification of volume fraction and size of the primary α, various solution heat treatments were conducted in the (α+β) field. Strength as well as ductility was maximized at a critical distribution of the primary α in the bimodal microstructure, where volume fraction and average size were 9.0% and 74.1㎛², respectively. Both of the strength and the ductility improvement were dominantly affected by volume fraction rather than average size of the primary α. The strength improvement is due to the combination of dominantly existing strengthened lamellar matrix and of finely distributing hardened primary α. Ductility improvement is obtained as a result of combined resistance to the microvoid generation and microcrack proipagation at a critical amount of the primary α. Microvoid generation and microcrack propagation are dominantly appeared at the conditions of less and more than the critical amounts of the primary α, respectively. Resistance to the microcrack propagation gives better ductility rather than microvoid generation in the bimodal structured Ti-6Al-4V alloy. |