Submicron bioactive glass fibers 70S30C (70 mol% SiO(2), 30 mol% CaO) acting as bone tissue scaffolds were fabricated by electrospinning method. The scaffold is a hierarchical pore network that consists of interconnected fibers with macropores and mesopores. The structure, morphological characterization and mechanical properties of the submicron bioactive glass fibers were studied by XRD, EDS, FIIR, SEM, N(2) gas absorption analyses and nanoindentation. The effect of the voltage on the morphology of electrospun bioactive glass fibers was investigated. It was found that decreasing the applied voltage from 19 to 7 kV can facilitate the formation of finer fibers with fewer bead defects. The hardness and Young's modulus of submicron bioactive glass fibers were measured as 0.21 and 5.5 GPa, respectively. Comparing with other bone tissue scaffolds measured by nanoindentation, the elastic modulus of the present scaffold was relatively high and close to the bone.

The relationships between indentation responses and Young's modulus of an indented material were investigated by employing dimensional analysis and finite element method. Three representative tip bluntness geometries were introduced to describe the shape of a real Berkovich indenter. It was demonstrated that for each of these bluntness geometries, a set of approximate indentation relationships correlating the ratio of nominal hardness/ reduced Young's modulus H n /E r and the ratio of elastic work/total work W e /W can be derived. Consequently, a method for Young's modulus measurement combined with its accuracy estimation was established on basis of these relationships. The effectiveness of this approach was verified by performing nanoindentation tests on S45C carbon steel and 6061 aluminum alloy and microindentation tests on aluminum single crystal, GCr15 bearing steel and fused silica.

A new Cu-based Cu-Zr-Al glassy alloy has been found to exhibit very high glass-forming ability, wide supercooled liquid region and high fracture strength. The addition of Al to a binary eutectic Cu 55 Zr 45 alloy significantly increases the stabilization of supercooled liquid as well as glass-forming ability in Cu 55Àx Zr 45 Al x (x ¼ 0 to 10) alloy series. The largest supercooled liquid region of 80 K, reduced glass transition temperature of 0.60 and value of 0.417 are simultaneously obtained for a ternary eutectic Cu 47 Zr 45 Al 8 alloy, which can fabricate fully glassy sample with critical diameters up to 15 mm by copper mold casting. The bulk glassy alloy also exhibits high compressive fracture strength of over 1900 MPa and the high Young's modulus above 100 GPa.