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A Cu-and Ni-free Zr-based metallic glass with high glass-forming ability was found in the Zr-Al-Co ternary system. The eutectic Zr 56 Al 16 Co 28 alloy could be cast into glassy cylindrical rods with diameters up to 18 mm. The glassy alloy exhibited high tensile fracture strength of 1830 MPa and low Young's modulus of 83 GPa in conjunction with better corrosion resistance compared with the glassy Zr 57 Nb 5 Al 10 Ni 12.6 Cu 15.4 in a simulated body fluid. Hydrothermal-electrochemical treatment in the aqueous 5M-NaOH solution resulted in the formation of amorphous sodium cobaltate layer on the surface of glassy Zr 56 Al 16 Co 28 alloy. Hydroxyapatite was spontaneously formed on the surface of the alloy, indicating bioactivity after surface modification. The discovery of a Cu-and Ni-free Zr-based metallic glass with a critical diameter larger than 1 cm in conjunction with excellent mechanical properties, superior corrosion resistance, and good bioactivity may open up the application field as biomaterials.

In this paper, we have developed TiZrCuPd quaternary bulk glassy alloys which seem to be favorable for future application as biomaterials because of the absence of toxic elements such as Ni, Al and Be. A series of (TiZr) 50 (CuPd) 50 bulk glassy alloys exhibit high glass-forming ability (with critical diameters of 6 and 7 mm) and relatively large supercooled liquid region (ÁT x ) of over 50 K. This alloy system follows the three empirical rules for stabilization of supercooled liquid. The thermal stability of Ti 40 Zr 10 Cu 36 Pd 14 bulk glassy alloy was also examined in correlation with the origin for the high glass-forming ability.

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Thin cupric oxide (Cu2O) nanobelts with width of few tens of nanometers to few hundreds of nanometers were fabricated in anhydrous ethanol on nanoporous copper templates that was prepared via dealloying amorphous Ti40Cu60 ribbons in hydrofluoric acid solutions at 348 K. The Cu2O octahedral particles preferentially form in the water, and nanobelts readily undergo the growth along the lengthwise and widthwise in the anhydrous ethanol. The ethanol molecules serve as stabilizing or capping reagents, and play a key role of the formation of two-dimensional Cu2O nanobelts. Cu atoms at weak sites (i.e., twin boundary) on the nanoporous Cu ligaments are ionized to form Cu2+ cations, and then react with OH− to form Cu2O and H2O. The two-dimensional growth of Cu2O nanostructure is preferred in anhydrous ethanol due to the suppression of random growth of Cu2O nanoarchitectures by ethanol. Cu2O nanobelts have superior photodegradation performance of methyl orange, three times higher than nanoporous Cu.

New Ni-free bulk glassy alloys in the Ti 47:5 Zr 2:5þx Cu 37:5Àx Pd 7:5 Sn 5 (x ¼ 0; 5; 7:5) system were fabricated by copper mold casting with diameters from 1 to 3 mm, which are expected to be applied as biomaterials. The structure, thermal stability and corrosion resistance were investigated by X-ray diffraction, differential scanning calorimetry and electrochemical measurement, respectively. Surface information after immersion in Hanks' solution was also characterized by using XPS. The results indicate that the bulk glassy alloys examined are spontaneously passivated. By anodic polarization, they show the passive current densities between 10 À2 and 10 À3 A/m 2 . The higher corrosion resistance for the Ti-based bulk glassy alloys is attributed to the formation of stable and protective passive films enriched with titanium and zirconium.