Development of Core-shell SiC nanoparticles for Ti-based nanocomposite alloys for additive manufacturing techniques

Introduction. The use of nanoparticles in 3D printing is progressing rapidly, and polymeric materials have benefited from the addition of carbon nanotubes, graphene, etc. to improve mechanical properties and contribute to... [ view full abstract ]

Introduction. The use of nanoparticles in 3D printing is progressing rapidly, and polymeric materials have benefited from the addition of carbon nanotubes, graphene, etc. to improve mechanical properties and contribute to lightweight. Unfortunately, to get an effective dispersion of nanoparticles in order to take maximum advantage, high energy processes are required and even these do not provide the expected mechanical performance. NANOTUN3D EU project [1] aims to improve the mechanical performance of Ti64 alloys by effective dispersion of SiC NPs. NANOTUN3D will provide an innovative concept to solve that limitation and improve the dispersion of SiC nanoparticles based on core-shell structures.

Results and discussion. The synthesis of core-shell nanoparticles was based on the direct formation of metal oxides on top of SiC nanoparticles by acidic hydrolisis of precursors. Nanoparticulated SiC material as core was characterized by X-ray diffraction, and transmission electron microscopy. The homogeneity of the metal oxide shell has been analysed by means of the Scanning Transmission Electron Microscopy (STEM) coupled with energy-dispersive X-ray spectroscopy (EDS) techniques. Characterization revealed that SiC nanoparticles corresponds with desired b-SiC phase with an average size around 42nm. STEM image 1 correspond to a preparation of MO₂@SiC core-shell nanoparticles with a Si:M molar ratio of 9.4 and shows a total overlapping of the two X-ray signals coming from metal and silicon atoms. This study confirmed that shell with 10 nm thickness was homogeneously distributed on SiC nanoparticles.

Conclusions.- Homogeneous precipitation of metal oxides in the presence of the SiC nanoparticles produces a homogeneous thin shell which can contribute to improve their dispersion into Ti6Al4V metal powder for additive manufacturing techniques. Obtained core-shell nanoparticles have been scale-up at a pilot level and next stage is the application of those nanoparticles to the production of a Ti6Al4V metal powder to be processed by additive manufacturing techniques with powder bed fusion –selective laser melting (SLM) and electron beam melting (EBM)- with enhanced structural performance versus standard alloy

 [1] NANOTUN3D project funded by EU H2020 Programme under grant agreement nº 685952. http://www.nanotun3d.eu