Study Of Hot Deformation Characteristics And Forming Process For TC11Titanium Alloy

TC11titanium alloy was widely used in the aerospace industry and used asthe research object in this paper. Isothermal compression of the TC11titaniumalloy has been conducted on Gleebe-1500D hot-simulator at the deformationtemperature ranging from960℃to1050℃, the strain rate ranging from0.01s-1to10s-1. According to the experimental data, constitutive equations and hotprocessing map are established, combined with the compressed tissue samplesanalysis, preliminary optimized TC11titanium alloy deformation process. Onthis basis, through the numerical simulation analysis of TC11titanium alloy hotextrusion process, obtained the temperature and velocity field of the stress onthe material impact of the law, resulting in optimized deformation process, andusing the process on the TC11titanium alloy forged, after forging theorganization and performance on work piece are analyzed.The results show that, the flow stress of TC11titanium alloy decrease withincreasing temperature and decreasing stress, its stress-strain curve is hardeningfirst after soften type. With the data of true stress-true strain curve, theconstitutive equation of TC11titanium alloy during hot deformation isestablished based on hyperbolic sine equation of Arrhenius type, the erroranalysis found that the established constitutive equation can objectively explainthe characteristics of TC11titanium alloy.Considering both processing maps and metallographic microstructure andscanning the microstructure in different areas after deformation. The instabilityarea and stability area of TC11titanium alloy processing maps can be confirmed.Instability area is during deformation temperature ranging from990℃to1020℃,strain rate for10s-1. It is easy to appear adiabatic shearing zone and sectionrheological instability phenomena. Stability areas are during deformationtemperature ranging from960℃to990℃and from1020℃to1050℃, strain rateranging from0.01s-1to1.0s-1.The numerical simulation analysis of TC11titanium alloy hot compressionprocess was studied based on the constitutive equation. The results show that thestress of material is so uneven to easily lead to instability or cracking with theincreasing of strain rate and the stress is more even with the increasing oftemperature.Based on the analysis of hot processing maps and numerical simulation, therecommended optimum thermal process parameter is at the deformationtemperature of1020℃, strain rate of1.0s-1. By the forging experimental verification, forgings as this parameter for processing have good performance.