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The use and application of alloys as biomedical alloys have increased over the past few years owing to their excellent biocompatibility, corrosion resistance, high mechanical and fatigue resistance, low density, adequate wear resistance, and low elastic modulus. Orthopedic implant materials are exposed to high mechanical loading. Conventional materials based on Ti-6Al-4V, stainless steel or cobalt-chromium alloys demonstrate good mechanical strength, but also some toxicological concerns due to release of toxic elements which may result in inflammatory reactions. Metal alloys based on titanium, zirconium, tantalum and niobium represent higher biocompatibility with appropriate mechanical properties for avoiding stress-shielding and consecutive implant loosening. Application of specifically designed spherical β-titanium alloy powders in additive manufacturing, such as selective laser melting (SLM) or electron beam melting (EBM); enable the production of components with a high degree in freedom of design. Accordingly, SLM or EBM of Ti/Nb (/Ta) alloys offer the possibility to fabricate patient-specific orthopedic implants. The present paper describes development of β-titanium alloys powders designed for application in additive manufacturing technologies. TiNbZrTa (TNZT)-based 3D structures were successfully manufactured and mechanically tested.

We have developed a new material for neutron shielding applications where space is restricted. W 2 B is an excellent attenuator of neutrons and gamma-rays, due to the combined gamma attenuation of W and neutron absorption of B. However, its low fracture toughness (∼3.5 MPa) and high melting point (2670 • C) prevent the fabrication of large fully-dense monolithic parts with adequate mechanical properties. Here we meet these challenges by combining W 2 B with a minor fraction (43 vol.%) of metallic W. The material was produced by reaction sintering W and BN powders. The mechanical properties under flexural and compressive loading were determined up to 1900 • C. The presence of the ductile metallic W phase enabled a peak flexural strength of ∼950 MPa at 1100 • C, which is a factor of 2-3 higher than typical monolithic transition-metal borides. Its ductile-brittle transition temperature of ∼1000 • C is typical of W-based composites, which is surprising as the W phase was the minor constituent and did not appear to form a fully continuous network. Compression tests showed hardening below ∼1500 • C and significant elongation of the phase domains, which suggest that by forging or rolling, further improvements in ductility may be possible.

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