The flow line evolution of hot open ACDR process for titanium alloy discs

Compared with traditional forging of titanium discs, the particular advantage for ACDR (axial closed die rolling) process is saving forming loading, but the weighted coefficient of compression and torsion happened on ACDR process show ambiguous even at the same axial forging ratio. Summed up from previous research, plastic yield process at ACDR forming is not only affected by the main stress caused from axial deformation, but also affected by shear stress from circumferential deformation. Flow line evolution as one of the manifestations, especially the circumferential deformation, should be studied to as basic theory to predict metal flow order, furthermore to define the deformation extent during ACDR process. Thus, this article presents flow line evolution laws with the three directions under different process conditions, emphasizing the difference of flow line evolution at different processing and the influence of process parameters associated with circles number n with the each direction. To achieve this purpose, numerical simulation with the essential boundary condition has been built. By means of systematic studying and discussing among deformation modes (stamping/machining, forging, high-pressure torsion, ACDR forming) and the process parameters (n, η, v, ω), the evolution law of flow line during hot ACDR on titanium alloy discs is achieved.