Density functional theory calculations were used to investigate the stability of single walled carbon nanotubes (CNTs) attached to nanoparticles. The total energies and the adhesion energies between the CNTs and the nanoparticles were calculated for systems where the nanoparticles were either pure Ni or Ni carbide. It was found that the adhesion between the CNT and a pure Ni cluster is stronger...

The composition of co-precipitated and collocated NbC carbide precipitates, Fe3C iron carbide (cementite), and Cu-rich precipitates are studied experimentally by atom-probe tomography (APT). The Cu-rich precipitates located at a grain boundary (GB) are also studied. The APT results for the carbides are supplemented with computational thermodynamics predictions of composition at thermodynamic eq...

A TEM study of pure tantalum and tantalum-tungsten alloys explosively shocked at a peak pressure of 30 GPa is presented. While no omega phase was found in shock-recovered pure Ta and Ta-5W which mainly contain a cellular dislocation structure, a shock-induced omega phase was found in Ta-10W which contains evenly distributed dislocations with a density higher than 1 × 10(12) cm( - 2). The shock-...

In the production of high speed steel, the rolling aaects the micro-structure of the steel, which in turn innuences the mechanical properties. Specii-cally, the distribution of carbide is essential, since cracks propagate within the carbide agglomerations. In current quality control, the properties of the steel are assessed manually by comparison with a standard chart, containing representative...

OBJECTIVES The aim of this study was to determine the apical surface characteristics and presence of dental cracks in single-rooted premolars, resected 3.0 mm from the root apex, using the Er: YAG laser, tungsten carbide bur, and diamond-coated tip, by scanning electron microscopy (SEM). EXPERIMENTAL DESIGN Thirty single-rooted premolar teeth were collected. The instrumented and obturated tee...

The Ni-based coatings with different content of spherical tungsten carbide were deposited by plasma transfer arc welding (PTAW) method on 304 austenitic stainless steel sheets in this study. The microstructure and wear property of spherical tungsten carbide particle reinforced composite coatings were investigated by means of optical microscope, scanning electron microscope (SEM), X-ray diffract...

1,3-Disilabutane is used as a single-source precursor to deposit conformal silicon-carbide films on silicon atomic-force-microscopy cantilevers. By measuring the resonance frequency of the cantilever as a function of silicon-carbide film thickness and developing an appropriate model, the value of the film’s elastic modulus is determined. This value is in good agreement with those reported for s...

Silicon carbide (SiC) has found a variety of engineering applications due to its superior properties. However, it is still desirable to study cost-effective processes to machine silicon carbide. This paper presents the results of a designed experimental investigation into Rotary Ultrasonic Machining (RUM) of silicon carbide. A four-variable two-level full factorial design was employed to reveal...

The mechanical properties, corrosion resistance and biocompatibility of the titanium-tantalum alloys together with pure titanium are comparatively studied for biomedical applications in this study. The experimental results confirm the previous theoretic investigation that tantalum has a potential to enhance the strength and reduce the elastic modulus of titanium alloys at the same time, and ind...