Takayoshi Nakano

A novel equiatomic TiNbTaZrMo high-entropy alloy (HEA) was developed as a new metallic biomaterial. The constituent elements of the HEA were biocomparable, and the HEA was designed based on parameters such as the mixing enthalpy (ΔHmix), the omega parameter (Ω), the delta parameter (δ), and the valence electron concentration (VEC) theory. The bcc solid solution phases with the different lattice constants were obtained in as-cast and annealed states. The HEA showed considerable strength with defo

We first developed a unique "crystallographic lamellar microstructure" (CLM), in which two differently oriented grains appear alternately, in a 316L stainless steel specimen via selective laser melting technology. The CLM was composed of major 011 grains and minor 001 grains aligned along the build direction, which stemmed from vertical and approximately 45inclined columnar cells formed in the central and side parts of melt-pools, respectively. The development of CLM was found to largely improve

• Fabrication of Ni-25 at.%Mo product was succeeded by the selective laser melting. • Texture development can be controlled by changing the scanning strategy of the laser. • Aligned crystal orientation along the build direction can be varied in 〈001〉 or 〈101〉. • Controlling mechanism of the texture was clarified by microstructure observation. Variations in the crystallographic texture in Ni-25 at.%Mo alloys fabricated by selective laser melting with different scanning strategies were designed fo

This paper clarified a novel strategy to improve the tensile properties of the Ti-48Al-2Cr-2Nb alloys fabricated by electron beam melting (EBM), via the finding of the development of unique layered microstructure composed of duplex-like fine grains layers and coarser γ grains layers. It was clarified that the mechanical properties of the alloy fabricated by EBM can be controlled by varying an angle θ between EBM-building directions and stress loading direction. At room temperature, the yield str

Nobel non-equiatomic Ti-Nb-Ta-Zr-Mo high-entropy alloys (HEAs) for metallic biomaterials (bio-HEAs) were designed and developed. The pseudo-binary phase diagrams focusing on solidification were constructed by thermodynamic calculations. The shifting the alloy composition of the equiatomic TiNbTaZrMo bio-HEA can realize the drastic improvement of the deformability. Notably, the non-equiatomic Ti, Zr-rich composition stimulated the molecular interaction between biological cells and bio-HEA, indica

Applying empirical alloy parameters (including Mo equivalent), the predicted ground state diagram, and thermodynamic calculations, noble nonequiatomic Ti–Zr–Hf–Nb–Ta–Mo high-entropy alloys for metallic biomaterials (BioHEAs) were designed and newly developed. It is found that the Moeq and valence electron concentration (VEC) parameters are useful for alloy design involving BCC structure formation in bio medium-entropy alloys and BioHEAs. Finally, we find a Ti28.33Zr28.33Hf28.33Nb6.74Ta6.74Mo1.55

Our knowledge of infant perception and cognition is primarily based on habituation and dishabituation, but the underlying neural mechanisms for these processes per se remain unclear. It has been argued that habituation is related to building internal representations of repeated stimuli in the central nervous system, whereas dishabituation is related to an increased attention to novel items and events. This leads to a hypothesis that a distributed network including the sensory, association and pr