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....

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...

Mechanical strengthening by grain refinement is a method whereby a material’s strength and hardness can be increased by decreasing the average crystallite grain size. The empirical Hall–Petch relationship mathematically describes grain boundary strengthening and provides guidance for a straightforward way to produce stronger materials. While the phenomenon has been widely explored in nanocrysta...

Bulk nanocrystalline Ti bars (Grade 4, Φ4 × 3000 mm(3)) were massively fabricated by equal channel angular pressing (ECAP) via follow-up conform scheme with the microcrystalline CP Ti as raw material. Homogeneous nanostructured crystals with the average grain size of 250 nm were identified for the ECAPed Ti, with extremely high tensile/fatigue strength (around 1240/620 MPa) and adorable elongat...

This manuscript describes a synthesis of nanocrystalline TiOF2 film. The nanocrystalline TiOF2 becomes chemically attached to the surface of the glass slide. These films are robust and can be recycled as photocatalysts for the degradation of organic dyes and solvents. These films also have significant antibacterial properties upon irradiation.