Investigation of Deformation Behavior of TC4 Titanium Alloy Bolt in Warm Forming

DOI: https://doi.org/10.62517/jes.202602210

Author(s)

Yufei You1,2, Peng Cheng1,2,*, Chenxi Shao1,2

Affiliation(s)

1Yanqi Lake Institute of Basic Manufacturing Technology Research (Beijing) Co., Ltd., Beijing, China 2China Academy of Machinery Science and Technology. Beijing, China

Abstract

TC4 titanium alloy is widely used in the manufacture of high-end aerospace fasteners due to its excellent specific strength and thermal stability. However, during warm forming, it is prone to cracking, uneven filling, and complex microstructure evolution, which restrict forming quality and process stability. This study takes TC4 titanium alloy bolts as the research object to investigate the deformation behavior during warm upsetting. Through Gleeble-3500 thermal simulation experiments, the true stress-strain curves of TC4 material are obtained within the temperature range of 800-1010 ℃ and strain rate range of 0.001-10s-1. Meanwhile, a thermo-mechanical-microstructural coupled finite element model is established based on DEFORM-3D to simulate the metal flow, equivalent stress distribution, equivalent strain distribution, forming load, and temperature field evolution during the three-step warm upsetting process. Based on heat loss analysis, the heat dissipation behavior during multi-station forming is revealed, showing that the billet temperature increases significantly during the forming stage of each step. Forming experiments are carried out on a warm upsetting production line, and the finite element model is validated using a high-precision coordinate measuring machine. The results show that the simulated geometric dimensions of the forged parts are in good agreement with the experimental results, with a relative error of less than 1.5%. The three-step forming process effectively avoids defects caused by a single large deformation, and the metal flow lines are uniformly distributed without obvious distortion or underfilling. The forming load increases stepwise, with a peak load of approximately 219 kN. The numerical model and analysis methods established in this study provide a theoretical basis and engineering reference for the optimization and quality control of the warm forming process of TC4 titanium alloy bolts.

Keywords

TC4 Titanium Alloy; Warm Upsetting; Deformation Behavior; Metal Flow Lines; Heat Loss Analysis

References

[1] Li D, Feng S W, Shi Y H, et al. The status and development tendency of aerospace fasteners. Astronautical Systems Engineering Technology, 2024, 8 (5): 1-8. [2] Whittaker J T, Hess D P. Ductility of titanium alloy and stainless steel aerospace fasteners. Journal of Failure Analysis and Prevention, 2015, 15 (5):571-575. [3] Zhang M, Lei J K, Wan Z Y, et al. Study on Thermal Tensile Behavior and Microstructure of Ti-6Al-4V Alloy. Technology Innovation and Application, 2025, 15(36): 17-21+25. [4] Shi J X, Zhao H. Effect of Heat Treatment Process on Microstructure and Mechanical Properties of Ultrafine-Grained TC4 Titanium Alloy. Rare Metals and Cemented Carbides, 1-11 [2026-04-16] [5] Liu J Q, Liang X R, Li Xiang, et al. Microstructure Evolution and Cracking Failure Analysis of TC4 Titanium Alloy during Warm Upsetting. Journal of Plasticity Engineering, 2026, 33(03): 24-31. [6] Yuan B, Chen S, Chen M, et al. Influences of hydrogen and compression speed on the room-temperature deformation mecha nisms of TC21 titanium alloy. International Journal of Hydro gen Energy, 2024, 81: 1224-1234. [7] Singh G, Souza P M. Hot deformation behavior of a novel alpha + beta titanium alloy TIMETALⒸ407. Journal of Alloys and Compounds, 2023, 935:167970. [8] Zhang C, Li D S, Li X Q. Simulation study on material flow of non-uniform cross-section titanium alloy profile under hot stretch bending under isothermal conditions. Journal of Plasticity Engineering, 2020, 27(12): 158-163. [9] Li B J, Wu C J. Effect of heating temperature and deformation speed on properties of TC4 alloy. Forging & Stamping, 2026, (07): 73-77. [10] Qu M J. Study on hot stamping process with cold die for TC4 titanium alloy box-shaped part. Jilin University, 2024. [11] Liu X T, Shuang Y H, Hu J H, et al. Establish ment and verification of constitutive model for hot tensile deforma tion for TC4 titanium alloy in rolled state. Forging & Stamping Technology, 2025, 50 (12):248-253. [12] Li P A, Song Y Q, Wei C, et al. Constitutive mod eling and microstructure evolution of TC4 titanium alloy in dual phase zone based on strain compensation . Forging & Stamping Technology, 2025, 50 (5):259-267. [13] Imran S M, Li C, Lang L, et al. An investigation into Arrhe nius type constitutive models to predict complex hot deformation be havior of TC4 alloy having bimodal microstructure. Materials Today Communications, 2022, 31:103622.