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This paper describes work to study oxidation and hot corrosion damage in nickel disc alloy RR1000. Oxidation damage has been characterised via mass change data from thermogravimetric analyses at temperatures from 700 to 800 ºC and cyclic oxidation testing at 700 and 750 ºC. Thin oxide scales rich in Cr and Ti have been found to grow in a parabolic dependence with time. Oxidation rate constants have been correlated with temperature using an Arrhenius equation. Through the use of simplifying assumptions, mass change data have been converted to oxide thickness values. These values have been compared with observed values of oxide scale and the depth of near-surface damage, which have been measured using focused ion beam (FIB) microscopy.Hot corrosion of RR1000 has been studied in the laboratory by 'deposit' recoat experiments at 700ºC. In these tests, samples were coated with deposits of Na 2 SO 4 /NaCl salt in a gas stream of air-300 vpm SO 2 . Corrosion damage has been quantified by dimensional metrology of samples before and after exposure. This enabled metal losses, i.e. the depth of corrosion pits, to be determined. Distributions of metal loss data were then generated to produce median damage values and exceedance cumulative probabilities. Finally, the effect of contaminants on the hot corrosion resistance of RR1000 has also been evaluated.

The microwave absorption properties of arrays of magnetic nanowires electrodeposited in nanoporous membranes have been studied using a strip transmission line configuration. From the measurements, the ferromagnetic resonance properties of the magnetic wires have been extracted at frequencies ranging from 100 MHz to 40 GHz for various angles between the wire axis and an external static magnetic field up to 8 kOe. We report on extensive data obtained on the ferromagnetic resonance properties in arrays of nanowires of Ni, NiFe, and NiFeCo alloys with various diameters and packing densities. In such arrays, apart from the shape anisotropy, a strong dipolar coupling between wires is present which can be modulated by the wire density. Both ferromagnetic resonance spectra and hysteresis loops show that this coupling acts as an additional uniaxial anisotropy favoring an easy axis perpendicular to the wires. In particular, it is shown that the easy axis of magnetization can be tuned parallel or perpendicular to the wire axis by changing the wire packing density. Furthermore, ferromagnetic resonance occurs even at zero field and the resonance frequency is fixed by the saturation magnetization of the material independent of the packing density.

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