Demands are increasing for micro axis-symmetric aspherical lenses to be installed in various optical devices. The micro glass lenses are generally molded by glass press process with micro aspheric ceramic molding dies or molds made of tungsten carbide or silicon carbide. These dies and molds are mostly ground with micro diamond wheels, but require additional finishing process as the size of the...

Critical cleavage stress values and carbide sizes obtained in a recent work by Lee et al. [1] are recalculated using 2D and 3D FE simulations and new constitutive law, instead of small scale yielding assumption and likely improper choice for the behavior of SA 508 steel. A new model based on the weakest link concept with the determined carbide size distribution (CSD) is succesfully applied to p...

–– Modern electronic design is constrained by the ability to package working computational systems. The packaging, which includes chip packaging, circuit boards, mounting, and ancillary support (such as heat dissipation), often constrains high–end design and imposes artificial limits on performance. After examining the " ideal " circuit board material it becomes apparent that silicon carbide of...

The effects of calcium carbide waste on some groups of soil microorganisms and soil enzymes were studied using standard microbiological and biochemical techniques. Soil samples were collected from a vehicle maintenance area as well as from an adjacent farm land (control) during the dry and rainy seasons. The population of all the bacterial groups in the different seasons was affected adversely ...

In this paper, an attempt has been made to experimental investigation the machinability of aluminum metal matrix composite (LM13/SiC/15p) during continuous turning of composite rods using carbide inserts. Base matrix material is Aluminium LM13 reinforced with 15 % weight by volume of Silicon carbide particles of mean diameter 20 μm to 40 μm is used. The main focus of investigation is to determi...

We present an introduction to the rapidly growing field of epitaxial graphene on silicon carbide, tracing its development from the original proof-of-concept experiments a decade ago to its present, highly evolved state. The potential of epitaxial graphene as a new electronic material is now being recognized. Whether the ultimate promise of graphene-based electronics will ever be realized remain...

this study is about complexes of li doped silicon carbide nanotube with thymine and cytosine ingas phase and aqueous solutions. li doped silicon carbide nanotube and its pyrimidine nucleobasecompounds were first modeled by quantum mechanical calculations in gas phase and in water.calculated binding energies indicated the stronger ability of thymine to functionalize silicon carbidenanotube than ...

Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to measure the concentrations of cobalt, tantalum, titanium, vanadium and chromium in solutions of tungsten carbide. The main advantage of the method described here lies in the speed, convenience and effectiveness of the dissolution procedure. Aliquots of powdered tungsten carbide were dissolved in a solution of 5% aqua...

The corrosion resistance of electroless nickel (EN) coatings on ferrous substrates is affected by coating porosity. Carbon and iron carbide are present in the microstructure of ferrous alloys. If the sites of carbon and iron carbide are not catalytically active to EN deposition as the rest of substrate surface, there is a possibility of pore formation on these sites. In the present study, the r...

We report on the laser ablation of composite prismatic structures using a vacuum ultraviolet (VUV) 157 nm F2 laser. Polycarbonate and CR-39 substrates have been intentionally seeded with silver wires and silicon carbide whiskers respectively. The seed particles remain attached to the underlying substrate after laser ablation, forming composite silver-polycarbonate and silicon carbide-CR-39 inte...