Complex-Shaped Implants Prepared by Selective Laser Melting

This contribution presents recent developments on free-formed NiTi structures aimed for biomedical applications such as dental or cranio-maxillofacial implants. The additive manufacturing method of selective laser melting (SLM Realizer 100, SLM-Solutions, Lübeck, Germany) allows producing complex-shaped objects with designed porosity and inner micro-architectures directly out of CAD data. Here, a laser scans the contours layer-wise in a bed of binary pre-alloyed spherical NiTi powder with a particle size of roughly 60 µm (A_f about -18 °C). The induced energy densities to locally melt the powder were varied changing laser and scanning parameters.

The differential scanning calorimetry (DSC), X-ray diffraction (XRD) and metallographic investigations (SEM) served for the extraction of the transition temperatures, the related crystallographic phases and the microstructure of the SLM constructs to investigate their dependence on the SLM process parameters. The ultimate goal lies in tailoring SMA properties of complex-formed NiTi microstructures for the realization of smart implants with defined micro-architectures and advanced performance.