3D Forging Simulation of a Multi-Partitioned Titanium Alloy Billet for a Medical Implant

Abstract

The medical healthcare industry uses titanium and its alloys to manufacture structural implants such as hip and knee replacement joints, which require an interface with bone, as well biocompatibility with soft tissue. These components can be manufactured with a variety of processing routes; however, forging has been one of the traditionally used, successful methods. In order to enhance a medical implant component’s properties such as fracture toughness, strength, microstructure and biocompatibility, it is of interest to understand a capability to develop forging methods which can produce a finished component such that different initial partitions of the billet occupy specific locations. As such, a 3D finite element (FE) modelling framework was established to simulate the coupled thermal and mechanical processes experienced during the forging of a workpiece containing multiple titanium-alloy material partitions, using the commercial FE software, Deform. A series of four models were simulated which contained differing arrangements of partitioning the initial billet, with different titanium alloys assigned to partitions. The forging operation was simulated with the same nominal processing parameters. The locations of these partitions within the final forging have been predicted, with varying success. One partition combination gave a very unsuccessful filling of the die, whilst the other models all filled the die correctly, and had different partitions maintained at key component locations. Thus, allowing for a manufacturing methodology to be presented which can potentially target specific component locations for specific materials to enhance component performance.