in the present study, nanocrystalline ni50al50-xmox (x = 0, 0.5, 1, 2.5, 5) intermetallic compound was produced through mechanical alloying of nickel, aluminum, and molybdenum powders. alni compounds with good and attractive properties such as high melting point, high strength to weight ratio and high corrosion resistance especially at high temperatures have attracted the attention of many rese...

We have conducted highP-Tsynchrotron X-ray and time-of-flight neutron diffraction experiments as well as indentation measurements to study equation of state, constitutive properties, and hardness of nanocrystalline and bulk nickel. Our lattice volume-pressure data present a clear evidence of elastic softening in nanocrystalline Ni as compared with the bulk nickel. We show that the enhanced over...

Solid solution strengthening in nanocrystalline alloys is studied using sputtered Ni–W as a model system. In the composition range of 0–20 at.% W, the sputtered alloys have a nanocrystalline structure with a grain size that is independent of composition. Nanoindentation of these alloys shows that solute addition increases strength to very high levels, almost in proportion to the solute content....

This paper reports a new technique that combines the features of Accumulative Roll Bonding (ARB) and Asymmetric Rolling (AR). This technique has been developed to enable production of ultra-thin bimetallic foils. Initially, 1.5 mm thick AA1050 and AA6061 foils were roll-bonded using ARB at 200°C, with 50% reduction. The resulting 1.5 mm bimetallic foil was subsequently thinned to 0.04 mm throug...

Aluminium foil is widely accepted as being one of the best barrier materials in flexible packaging, even in the face of many new and up-and-coming high-barrier plastic layer combinations, copolymers, blends or nano-composites. Besides high thermal conductivity, which facilitates enhanced converting and sealing performance, other key criteria that distinguish “converter foil” from competing mate...

Many fish depend primarily on their tail beat for propulsion. Such a tail is commonly modeled as a twodimensional flapping foil. Here we demonstrate a novel experimental setup of such a foil that heaves and pitches in a soap film. The vortical flow field generated by the foil correlates with thickness variations in the soap film, which appear as interference fringes when the film is illuminated...

Experimental methods are demonstrated for studying pressure-dependent material properties and solid phases unattainable at ambient pressure with high-pressure synchrotron nuclear resonance techniques. Pressure presents an intriguing experimental parameter for investigating the problem of excess low-energy (<12 meV) vibrational modes in nanocrystalline materials. A satisfactory explanation for t...

In this study, a novel multi-walled carbon nanotubes reinforced nanocrystalline copper matrix composite with super high strength and moderate plasticity was synthesized. We successfully overcome the agglomeration problem of the carbon nanotubes and the grain growth problem of the nanocrystalline copper matrix by combined use of the electroless deposition and spark plasma sintering methods. The ...

In our previous work (R.J. Asaro, P. Krysl and B. Kad, Philos. Mag. Lett. 83 (2003) p.733; P. Gu, B. Kad and M. Dao, Scr. Mater. 62 (2010) p.361), the intra-granular partial dislocation extension model was shown to be consistent with the experimental data of flow stress in nanocrystalline FCC materials. However, since the averaged extension was taken for a nonuniform loop, the model predicted s...

Impact of the in-situ rise of hydrogen partial pressure on graphene shape evolution during CVD growth of graphene Zewdu M.Gebeyehu, Aloïs Arrighi, Marius V. Costache, Clivia M. Sotomayor-Torres, Maria J. Esplandiu, Sergio O. Valenzuela Methods Copper foil preparation A 25 μm thick copper foil (99.8%, Alfa Aesar, stock #13382) was cleaned in acetone and isopropyl alcohol (IPA) for 10 min each to...