Simulation of stamping workpieces implants process using schemes of severe plastic deformation processes

Pure titanium is much more biocompatible than the alloys used in medicine but has low strength properties, which hinders its widespread use for the implants manufacturing. Providing the necessary level of strength characteristics requires the use of severe plastic deformation methods (SPD), because traditional methods of metal forming processes do not provide the desired set of properties. Designing the implant geometric model of spine spacer type and forgings for its production was performed. Forging form allows applying an SPD stamping process, which eliminates the need for pre-treatment of the workpiece material before punching. Process steps sequence are proposed as a result of an analysis of the “U-implant” part geometry using stamping deformation schemes corresponding to SPD schemes under plane strain state: sediment workpiece flat punch, three stamping operations of implant forgings that eliminate the preliminary preparation of the microstructure workpiece before punching. Analysis of options for implementing the transition process of plastic deformation using simulation in CAE-systems allowed us to determine the sequence of deformation stages and tool geometry, providing required metal flow. Cumulative degree of deformation during the billet forming is 3.3-7, which provides the necessary change in the structure and strength characteristics of the forging (at 400 °C temperature). The maximum value of the specific efforts in the calculation of the transition stamping does not exceed 160 MPa due to the choice of technological transitions in filling the die cavity draft, which ensures long tool life.