Borcarbid

BeschreibungSodium tetraborate decahydrate/borax (anhydrous) is a clear, colorless or pale yellow hygroscopic substance with a faint odor of detergent. It is stable and is incompatible with powdered metalsand slightly soluble in water. It is extensively used in the industrial manufacturing of metallurgical fluxes, fiberglass, ceramics, fertilizers, enamels, heat-resistant glass (e.g., Pyrex), and other chemicals. It decomposes on heating or on burning producing toxic fumes including sodium oxide, reacts with strong oxidants, and in fire gives off irritating or toxic fumes (or gases).

VerwendenBoron carbide (B4C) is a hard, black crystal that is used as an abrasive powder and as an additive to strengthen composite parts in aircraft.

synthetischeBoron carbide is prepared by reduction of boric oxide either with carbon or with magnesium in presence of carbon in an electric furnace at a temperature above 1,400°C. When magnesium is used, the reaction may be carried out in a graphite furnace and the magnesium byproducts are removed by treatment with acid.

Definitionboron carbide: A black solid, B4C,soluble only in fused alkali; it is extremelyhard, over 9 on Mohs’scale; rhombohedral; r.d. 2.52; m.p.2350°C; b.p. >3500°C. Boron carbideis manufactured by the reduction ofboric oxide with petroleum coke inan electric furnace. It is used largelyas an abrasive, but objects can alsobe fabricated using high-temperaturepowder metallurgy. Boron nitride isalso used as a neutron absorber becauseof its high proportion ofboron–10.