Characterisation of 3D Printed and Hybrid 3D Printed/Wrought Grade 23 Titanium Components for Orthopaedic Applications

The additive manufacture of Ti6Al4V is growing in market size every day. The presented thesis investigates the effect of changing parameters (layer thickness and laser power) on additively manufactured Ti6Al4V. Following this, the thesis introduces the concept of combining additive manufactured and wrought Ti6Al4V to create a novel hybrid material. This hybrid material provides a potential expansion of the usability of additive manufacture in part production, gaining some of the benefits of additive manufacture, without losing the practicality of more traditionally manufactured wrought material. This research explores the validity of the process, the mechanical and microstructural behaviour of the hybrid, and the processing parameters which are most applicable to hybrid manufacture. Microstructural analysis, Vickers hardness testing, and x-ray diffraction phase analysis are performed to analyse the effect of changing laser power and layer thickness on additively manufactured Ti6Al4V. Hybrid manufactured material is subjected to rigorous microstructural analysis, Vickers hardness testing, fatigue testing, fracture analysis, and tensile testing in order to investigate the effects the hybridisation process has on the material, when compared to their wrought and additively manufactured counterparts. These analyses are conducted successfully, providing a recommendation on an ideal parameter combination for DMLS-based additive manufacture. This combination was found to be a layer thickness of 60 µm manufactured at medium laser power. The analyses then provided confirmation on the validity of the hybridisation process, indicating comparable mechanical properties to both wrought and additively manufactured material. This research provides a solid foundation for the application of hybrid manufacture to produce novel hybrids of this type, along with giving ideal parameters for their manufacture.