Production of Fine-Grained Ti-6Al-4V ELI for Medical Implants Using Equal-Channel-Angular-Swaging

Multi-resistant bacteria pose a global threat, as infections can lead to life threatening conditions. In orthopaedics, implant surfaces are critical for infection prevention. Implants with a fine-grained surface are a promising way to achieve antibacterial properties by inhibiting biofilm formation. In this paper, the continuous manufacturing process for fine-grained materials called Equal-Channel-Angular-Swaging (ECAS) is applied to the most commonly used medical titanium alloy Ti-6Al-4V ELI. First, the homogeneity of the shear strain (which is crucial for grain refinement) is investigated in a numerical simulation under different process parameters (e.g. feedrate, counter pressure, number of passes). In the ECAS process, the material fails due to shear bands. Using the process parameters found in the simulation, damage free forming is possible. The material properties are discussed using microstructural analyses, hardness measurements and tensile tests.