Studies on the Characteristics of Process Parameters in

• Main Authors: Hsun-Chi Cheng, 鄭訓祺
• Other Authors: Rong-Shean Lee
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/06003825602460997205

碩士 === 國立成功大學 === 機械工程研究所 === 83 === The plastic behavior of Ti-6Al-4V alloy during isothermal forging has been studied. Using dimensionless spike height, flow patterns of forgings, flow line and forging load as indexes, the influence of the friction condition, the billet geometry and the ram speed on the forming characteristics of this titanium alloy was studied. A rigid-plastic finite element analysis of this i- sothermal forging operation on hydrulic forming machine is pre- sented by using two dimensional computer code DEFORM. The spike test, having lateral flow and axial filling, can be used to simulate the forging characteristics of most products with rib-web design. For titanium alloy, the flow stress in gen- eral has a high sensitivity to strain rate, so effect of ram speed on the dimensionless spike height was explored. Analyses on conventional forging and hot-die foring were also conducted, and the results showed that spike height of isother- mal forging is slightly smaller than that of conventional forg- ing, however, the forging load of isothermal forging is lower than that of conventional forging. The spike height constructed by this thesis can be used for preform design and die shape design.