|
Vol.43, No.12, 847 ~ 860, 2005
|
| Title |
| Special Edition : Symposium on Mechanical Behavior of Materials(2) ; Prediction of Microstructure During High Temperature Forming of Ti-6Al-4V Alloy |
| 이유환 You Hwan Lee , 염종택 Jong Taek Yeom , 박노광 Nho Kwang Park , 홍성석 Seong Seok Hong , 심인옥 In Ok Shim , 황상무 Sang Moo Hwang , 이종수 Chong Soo Lee |
|
|
|
| Abstract |
| A study has been made to investigate the high temperature deformation behavior of Ti-6Al-4V alloy and to predict the final microstructure under given forming conditions. Equiaxed microstructure of Ti6Al-4V alloy was prepared as starting microstructures. By performing the compression tests at high temperatures (700~1100℃) and a wide range of strain rates (10^(-4) ~ 10²/s), flow stress-strain curves obtained and various parameters such as strain rate sensitivity (m) and activation energy (Q) were obtained and used to established constitutive equations. When the specimens were deformed up to strain of 0.6, equiaxed microstructure did not show any significant changes in morphology, while the average α grain size was varied with variation of volume fraction at different temperatures and strain rates. Accordingly, constitutive equations were developed by use of internal state variables, and applied to predict the final microstructure after forming. Finally, the finite element analysis was performed considering the microstructural evolution during the hot deformation, and the grain size and the volume fraction of α phase of deformed body were predicted and compared with the experimental results through the actual forging process. |
|
|
| Key Words |
| Ti-6Al-4V alloy, Equiaxed, Hot Workability, Instability, Constitutive Equation, Processing Map |
|
|
 |
|
