Enhancement of Oxidation Resistance via Chromium Boron Carbide on Diamond Particles

Enhancement of oxidation resistance via a self-healing boron carbide coating on diamond particles

A boron carbide coating was applied to diamond particles by heating the particles in a powder mixture consisting of H3BO3, B and Mg. The composition, bond state and coverage fraction of the boron carbide coating on the diamond particles were investigated. The boron carbide coating prefers to grow on the diamond (100) surface than on the diamond (111) surface. A stoichiometric B4C coating comple...

Stabilization of boron carbide via silicon doping.

Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in ...

Enhancement of Surface Hardness: Boron on Diamond (111)

We have performed ab initio pseudopotential calculations for the diamond (111) surface with nitrogen or boron replacing the surface carbon atoms. Surface boron atoms form planar sp2 bonds with carbon atoms and the compressive stress from the underlying bulk diamond lattice squeezes the B-C bonds significantly. Bulk and shear moduli in the surface region increase substantially, surpassing those ...

Boron carbide/n-silicon carbide heterojunction diodes

Plasma spraying and characterization of chromium carbide – nickel chromium coatings

Chromium carbide – nickel chromium powder Cr3C2-25wt.NiCr was plasma sprayed by a water-stabilized system WSP®. A series of experiments with variable feeding distance was carried out. Basic characterization of coatings was done by XRD, SEM and light microscopy plus image analysis. Microhardness was measured on polished cross sections. The main focus of investigation was on resistances against w...