The paper reports the first successful fabrication of MgB 2 superconducting tape using a flexible metallic substrate as well as its strong pinning force, which was verified by direct measurement of transport critical current density. The tape was prepared by depositing MgB 2 film on a Hastelloy tape buffered with an YSZ layer. The J c of the tape exceeds 10 5 A/cm 2 at 4.2K and 10T, which is considered as a common benchmark for magnet application. The J c dependence on magnetic field remains surprisingly very small up to 10T, suggesting that the tape has much better magnetic field characteristic than conventional Nb-Ti wires in liquid helium.The newly discovered MgB 2 superconductor 1 is expected to be useful for various electric power applications as well as electronic device applications because its transition temperature is much higher than those of conventional metallic superconductors such as Nb-Ti and Nb 3 Sn. In order to evaluate the potentiality for p ower applications, the development of wire processing techniques is essential. The first attempt at wire fabrication was the magnesium vapor diffusion to boron fibers presented by Canfield et al 2 . Recent efforts at wire fabrication have centered on developing the powder-in-tube (PIT) process due to its greater easiness of scaled up production [3][4][5][6][7] . The transport critical current density J c at 4.2K and in self-field of the PIT processed tapes has already exceeded the practical level of 10 5 A/cm 2 . However, the J c rapidly decreases in an applied magnetic field due to its weak pinning force. The J c values at 4.2K and 10T reported so far for PIT processed wires and tapes remain as low as the order of 10 3 A/cm 2 , although the values are being steadily improved.In contrast to the relatively poor in-field J c values of the tapes and bulks, there are several papers on MgB 2 thin films, which reported very much higher Hc 2 values and J c values in applied magnetic fields than those of tape and bulk samples 8,9 . Kim et al 9 reported a large transport J c value of 10 5 A/cm 2 at 5T and 15K for the c-axis oriented MgB 2 film prepared on an Al 2 O 3 substrate. Those results suggest to us that the MgB 2 phase formed by vapor deposition techniques has extremely strong pinning force. However, all experiments on the thin films have been performed using ceramic substrates, which are not suitable for long length production of flexible conductor. This paper reports a successful new approach to fabricate MgB 2 tape that is the combination of the high critical current density achieved by vapor deposition and the use of flexible metallic substrate tape. The technique is similar to the so-called coated conductor techniques developed for YBa 2 Cu 3 O y (Y-123), where Y-123 thin films are deposited on various buffer layers on a metallic substrate 10 -12 . The MgB 2 tape obtained in this work has an excellent transport J c of 1.1x10 5 A/cm 2 at 4.2.K and 10T. It is also surprising that the J c dependence on the magnetic field remains extremely small up to 10T, ...

A 5th generation single crystal (SC) superalloy TMS-196 with improved microstructural stability and environmental properties was designed with using NIMS Alloy Design Program and evaluated experimentally. It was found that TMS-196 has a very stable microstructure even after 1000h creep at 1100 C and also very well balanced creep, TMF and environmental properties. TMS-196 also had excellent SC castability; sound cooling blades of up to 300mm long were successfully cast.

For jet engines to meet the ever-increasing demands of ecological compatibility, the compositions of Ni-base single-crystal superalloys have continuously evolved to cope with the increase in turbine entry temperature (TET) owing to the design that improve the thermodynamic efficiency of gas turbine engines. Over the past decade, the addition of Ru has been one of the main subjects of focus to enhance the temperature capability and contribute to the development of new generations of single-crystal superalloys. This paper reposts one of the latest Ru-bearing 6th generation superalloys developed by the National Institute for Materials Science (NIMS), TMS-238. TMS-238 is a promising candidate alloy for future turbine blade applications because it exhibits excellent and well-balanced mechanical and environmental properties.

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The 4th and advanced generation Ni-base single crystal superalloys, which contain large amounts of refractory metals for strengthening and platinum group metals, e.g., Ru, for TCP-phase prevention, show excellent high-temperature strengths. However, these alloying elements seem to decrease high-temperature oxidation resistance. In this study, Ni-base superalloys with various amounts of Ta, Re and Ru were examined in isothermal and cyclic exposures at 1373K to investigate the effect on the oxide growth rate and resistance to scale spallation. Structures of the oxide for the alloys were analyzed by XRD, SEM and EDX, and the oxidation kinetics is discussed. Ru and Re were found to degrade the oxidation resistance by the vaporization of their oxide. Ta-rich oxide in the spinel layer affects to stabilize ruthenium and rhenium oxide in the scale and improve the oxidation resistance of Ru-containing Ni-base superalloys.