FEM Simulation Of Thin-wall Sectional Rolling For Titanium Alloy

Thin-wall sectional bars of titanium alloy have been widely applied in recent years due to its low density, high specific strength and high corrosion resistance. However, its application is deeply influenced by the narrow process window and the low workability which make it quite challengable in the manufacturing and forming of titanium alloy sectional bar. In this work, commercial FEM code Deform software is used to simulate the sectional rolling process of titanium alloys to investigate the temperature and deformation distribution and evolution principles. Also the temperature and deformation for different passes show that the filling efficient and defects formation can be predicted and improved after FEM modeling. The rolled sections are evaluated from dimension tolerance, surface condition, microstructure and mechanical properties, respectively, and the experimental results show that FEM modeling results is comparable reliable and can be used for the improvement of rolling process. The preliminary results are as follows:1. FEM model is established to simulate the sectional rolling process of TA15alloy, and the simulation results agree well with actual measurement results, which shows the FEM model is comparable reliable in the sectional rolling process.2. Pass schedules are modified from nine passes to thirteen passes and rolling processes are improved from one heat to two heats to avoid excessive deformation in certain pass and cracks in the last several passes due to excessive heat loss.3. The average values of tensile strength, yield strength and elongation of sectional bar were satisfied according to the specification. Fine grained equiaxed microstructures with acceptable mechanical properties are obtained after optimized annealing process.4. Measurement results showed that the center of sectional bar was0.12mm thicker than the edge, which was in the allowable error range. The dimension tolerance of TA15thin-walled section bar is acceptable. The surface was relatively smooth but some cracks, grooves and other defects\were still found on it. Further researches should be done to improve the quality of surface.