Boron Carbide


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boron carbide

[′bȯ‚rän ′kär‚bīd]
(organic chemistry)
Any compound of boron and carbon, especially B4C (used as an abrasive, alloying agent, and neutron absorber).

Boron Carbide

 

(B4C; more correctly B12C3), a compound of boron and carbon. It is formed during the interaction of boron or boric anhydride with carbon at a temperature above 2000° C. It consists of black, shiny crystals with a density of 2.52 g/cm3 and a melting point of 2360° C. It is stable in air up to 1000° C and does not react to acids but is decomposed by alkalis. It exceeds corundum (Al2O3) and carborundum (SiC) in hardness and is softer only than diamond and borazon. It is used as an abrasive and grinding material, as a semiconductor, and also in nuclear engineering, as a neutron-absorbing material.

References in periodicals archive ?
Branscome and Essroc conferred with UK Abrasives Inc., which processes and markets Ukraine-sourced boron carbide in 4- to 125-micron gradations.
"It's theoretically harder than boron carbide, which is the material that we currently employ for body armor," Vargas-Gonzalez said.
Additionally one detects a weak feature at about 970 [cm.sup.-1] which is also visible in the previously measured spectra of crystalline and amorphous boron carbide [39, 40].
It belongs to the rhombohedral lattice R[bar.3]m space group, although a recent paper describes a second [B.sub.4]C phase with monoclinic structure, reopening the discussion about the boron carbide structure [13].
U.B.Gopalkrishna gave the result that maximum weight percentage of the boron carbide which can be added to the aluminium matrix phase is 15wt%, Adding the boron carbide beyond this weight percentage may leads to the aggravate situation which includes the reduction in the tensile and compressive stress[1].
The grains or powders of boron carbide are used as the abrasive.
Chapter 2, "Surface and Coating Materials Technologies and Engineering," consists of papers on the effect of ion implantation on mechanical stress, the influence of microarc oxidation on surface roughness, effects of high-powered pulsed ion beams on coating deposition, the use of a magnetoplasma accelerator on boron carbide coating formation, and heat and mass transfer in wet fibroporous material.
Improving physical and mechanical properties and sintering behaviour of composites by using silicon carbide (SiC) additives at nanometric and micrometric scales, molybdenum disilicide (MoSi2) and boron carbide (B4C) are among other objectives of the research.
Improving physical and mechanical properties and sintering behavior of composites by using silicon carbide (SiC) additives at nanometric and micrometric scales, molybdenum disilicide (MoSi2) and boron carbide (B4C) are among other objectives of the research.
The objective of this work is to investigate the tribological behavior of acrylonitrile butadiene styrene based composites filled with aluminum, boron carbide and glass spheres particles.
Likewise, several peaks were observed that correspond to crystalline phases such as chromium boron carbide [Cr.sub.3][B.sub.0.4][C.sub.1.6] (JCPDS File # 01-089-25-89), boron carbide [B.sub.13.3] CL 7 (JCPDS File # 01-083-0855), niobium carbide, [Nb.sub.6][C.sub.5] (JCPDS File # 01-077-0566), iron niobium, [Fe.sub.65][Nb.sub.6.5] (JCPDS File # 01-071-8308), tungsten, W (JCPDS File # 00-001-1203), and a Fe-Cr solid solution (JCPDS File # 00-034-0396).
Among specific topics are parameters that influence silica dissolution in alkaline media, the effect of basalt chopped fiber reinforcement on the mechanical properties of potassium-based geopolymer, a new anisotropic constitutive model for ceramic material failure, gas-phase reactivity during chemical vapor deposition of boron carbide, frontiers in nanomaterials and nanotechnology and the impact on society, and measuring thermal conductivity of graphitic foams.