A novel low-modulus titanium alloy for biomedical applications: A comparison between selective laser melting and metal injection moulding

The mechanical properties of new low-modulus beta titanium alloyed designed for biomedical applications are measured and compared when processed via the selective laser melting (SLM) and the metal injection moulding (MIM) processes. Mechanical tensile testing reveals important differences between them: (i) Under optimal laser settings, SLM produces strong, low-modulus and ductile properties. This is associated with the laser creating fully dense material with appropriate microstructure after solidification. (ii) MIM can produce materials with similar strength/stiffness ratios, but with reduced ductility. The differences between the processes are linked to changes in chemistry in the microstructure: carbon pickup from MIM binder and slow cooling rate is responsible for the appearance of Ti2C resulting in low ductility and very high strength together with a transition from intergranular to transgranular fracture.