A new Ti-based bulk-metallic glassy (BMG) alloy without Ni was developed in various forms such as melt-spun ribbon and cylindrical rods. Ti metal and Ti-based alloys are well known as biomaterials because Ti has good biocompatibility with the human body. We examined mechanical and chemical properties of a newly developed Ti-based BMG alloy in comparison with pure Ti metal and Ti-6Al-4V alloy, which are used for biomaterials. The new Ti-based BMG (Ti 45 Zr 10 Pd 10 Cu 31 Sn 4 ) alloy does not contain Ni, Al, and Be elements, which are known to be toxic. The Ti 45 Zr 10 Pd 10 Cu 31 Sn 4 BMG alloy rod with a diameter of 3 mm, which is produced by copper mold casting, exhibits a compressive strength of 1970 MPa and a Young's modulus of 95 GPa. In addition, the Ti 45 Zr 10 Pd 10 Cu 31 Sn 4 BMG alloy shows a supercooled liquid region of 56 K and a reduced glass-transition temperature, T rg (‫ס‬T g /T l ), of 0.56. The high thermal stability of supercooled liquid has enabled the fabrication of a cylindrical rod specimen with a diameter of 4 mm. This alloy exhibits precipitation of a primary nanoscale icosahedral phase upon devitrification followed by the formation of a metastable unidentified phase. Ti 2 Cu and Ti 3 Sn are stable phases formed in this alloy. The Ti 45 Zr 10 Pd 10 Cu 31 Sn 4 BMG alloy has a high corrosion resistance and is passivated at a lower passive current density of approximately 10 −2 A/m 2 compared to those of pure titanium and the Ti-6Al-4V alloy in 1 mass% lactic acid and phosphate-buffered saline solutions at 310 K.

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18Ni-300 maraging steel produced by the selective laser melting (SLM) process has a unique microstructure that is different from that of the same alloy processed by conventional methods. In this paper, maraging steels were fabricated by the selective laser melting process and their microstructures and mechanical properties were investigated in terms of post heat treatment conditions. Moreover, the effect of different heat treatments on the mechanical anisotropy was studied in detail. The micro Vickers hardness in the as-built state was around 340 Hv and could be increased to approximately 600 Hv by aging heat treatments. It was found that the solution heat treatment was not necessary to obtain a fully hardened state. From tensile tests of the maraging steels heat treated with different conditions, it was found that the highest strength was achieved by aging and solution treatment (ST) temperatures lower than the commonly used temperatures. In the direction parallel to the laser scanning, the highest ultimate tensile strength was obtained when 450 °C aging was done without solution heat treatment. In the other two directions tested, i.e., directions normal to the building and 45 degrees to the laser scanning direction, the highest tensile strength was obtained when aging was done at 450 °C after 750 °C solution treatment.

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