Additive manufacture (AM) is emerging as a viable manufacturing method for fabrication of metallic biomedical implants, aerospace components or parts on demand for energy sector. Further adaptation of AM technologies and new applications are hindered due to a limited range of available alloys suitable for laser metal additive manufacturing and difficulty in rapid development and testing of AM specific materials. One possible strategy is the use of in-situ alloying where elemental powders are blended either during the process, for instance in laser direct energy deposition or prior to the process in the laser powder bed fusion (L-PBF).

In this talk, an example system, namely TiTa alloys will be used to demonstrate the advantages of in-situ alloying and discuss some of the existing drawbacks [1-5]. The processing of this alloy using L-PBF process is challenging due to the refractory nature of Ta. The optimisation of processing parameters to produce fully dense samples with a minimised volume fraction of unmelted Ta particles is elaborated focusing on different processing strategies. The morphology of the resulting microstructures was analysed with scanning electron microscopy (SEM) and phase identification supported with X-ray diffraction (XRD) analysis. The material was then assessed for mechanical properties under static and cyclic loading. TiTa alloy showed similar strength to L-PBF titanium with half the elastic modulus and an altered microstructure caused by the ‘remelt’ scanning strategy. The alloy also demonstrated a superior yield stress normalised fatigue performance compared with commercially pure (CP) Ti, and Ti-6Al-4V ELI. The relationship between composition, microstructure and mechanical response of the TiTa alloy system will be presented.