Sliding wear of nanocrystalline Ni-W alloys with grain sizes from 3 to 45 nm, a range which spans the transition in deformation mechanisms from intrato intergranular, is studied through pin-on-disk wear testing. The extreme conditions produced during sliding wear are found to result in structural evolution and a deviation from Archard scaling for the finest grain sizes; in the finest nanocrysta...

Microcompression testing is used to probe the uniaxial stress–strain response of a nanocrystalline alloy, with an emphasis on exploring how grain size and grain boundary relaxation state impact the complete flow curve and failure behavior. The yield strength, strain hardening, strain-to-failure and failure mode of nanocrystalline Ni–W films with mean grain sizes of 5, 15 and 90 nm are studied u...

The stability of an electrodeposited nanocrystalline Ni-based alloy coating in a H₂S/CO₂ environment was investigated by electrochemical measurements, weight loss method, and surface characterization. The results showed that both the cathodic and anodic processes of the Ni-based alloy coating were simultaneously suppressed, displaying a dramatic decrease of the corrosion current density. The co...

Nanocrystalline ~NC! ferrite powders have been synthesized using a 50 kW–3 MHz rf thermal plasma torch for high-frequency soft magnet applications. A mixed powder of Ni and Fe (Ni:Fe 51:2), a NiFe permalloy powder with additional Fe powder (Ni:Fe51:2), and a NiFe permalloy powder (Ni:Fe51:1) were used as precursors for synthesis. Airflow into the reactor chamber was the source of oxygen for oxi...

In this study the effect of crystallite size reduction and microstructure on the electrochemical corrosion behavior of nanocrystalline nickel (NC Ni) were investigated using Tafel polarization and electrochemical impedance spectroscopy (EIS) measurements in 10 wt.% NaOH. NC Ni coatings were produced by direct current electrodeposition using chloride baths in presence and absence of saccharin as...