Zirconium carbide nitride

Electric Furna.ce, Zircon and coke have reacted in an electric arc furnace to produce a cmde zirconium carbide nitride [12713-24-5] (ca 6 wt %... 

Zirconium oxide is fused with alurnina in electric-arc furnaces to make alumina—zirconia abrasive grains for use in grinding wheels, coated-abrasive disks, and belts (104) (see Abrasives). The addition of zirconia improves the shock resistance of brittle alurnina and toughens the abrasive. Most of the baddeleyite imported is used for this appHcation, as is zirconia produced by burning zirconium carbide nitride. 

Zirconium carbide, 4 649t, 686 cemented carbides, 4 656 as industrial hard carbide, 4 674 physical properties of, 4 684t preparation, 4 675, 676 stoichiometry, 4 651 Zirconium carbide nitride, 26 627 Zirconium carbonitride... 

Zirconium carbide and zirconium carbide-nitride films on silver (ZrC-Ag and... 

Chlorination. Historically, the production of zirconium tetrachloride from zircon sand involved first a reduction to carbide nitride (see above) followed by the very exothermic reaction of the cmshed carbide nitride with chlorine gas in a water-cooled vertical shaft furnace ... 

Of a series of powdered refractory compounds examined, only lanthanum hexa-boride, hafnium carbide, titanium carbide, zirconium carbide, magnesium nitride, zirconium nitride and tin(II) sulfide were dust explosion hazardous, the 2 latter being comparable with metal dusts. Individual entries are ... 

Hafnium carbide, 0521 Lanthanum hexaboride, 0193 Magnesium nitride, 4698 Tin(II) sulfide, 4900 Titanium carbide, 0561 Zirconium carbide, 0565 Zirconium nitride, 4733... 

Hafnium carbide, 0518 Lanthanum hexaboride, 0193 Magnesium nitride, 4693 Tin(II) sulfide, 4894 Titanium carbide, 0558 Zirconium carbide, 0562 Zirconium nitride, 4728... 

Because the details of processing in each class of CMCs (e.g., oxide, carbide, or nitride matrix) are slightly different, the appropriate thermochemical approach for each class may also be different. For example, in the formation of alumina matrix materials by directed metal oxidation, the alumina product grows from a molten aluminum alloy by reaction with an oxygen-containing gas phase. On the other hand, in the formation of platlet-reinforced zirconium carbide, the gas phase is not involved in the reaction at all, being inert to the reactants and products. Thus, a general approach to deal with the myriad of possible products formed by the... 

In February, 1980, Sumitomo from Japan filed the patent Sintered compact for a machining tool and a method of producing the compact [161]. This patent basically covers any compact with 10-80 vol% cBN and a balance of binder material that can comprise any carbides, nitrides, borides, or silicides of metals of groups IVa, Va, or Via. Specifically mentioned are titanium, zirconium, hafnium, vanadium, niobium. 

It is sometimes considered advantageous to allow atmospheric nitrogen to take part in the reaction and form a mixture of zirconium carbide with nitride, referred to as the cyanonitride or carbonitride . This gives a more exothermic reaction with chlorine than the carbide itself. 

Christensen AN (1990) A neutron diffraction investigation on single crystals of titanium oxide, zirconium carbide, and hafnium nitride. Acta Chem Scand 44 851-852... 

Gerasimov et have provided a reference book on the thermodynamic properties of tungsten, molybdenum, titanium, zirconium, niobium, and tantalum, and their more important compounds, viz. oxides, sulphides, halides, carbides, nitrides, silicates, borides, and hydrides. 

Exposure limits for siHcon carbide and powders of zirconium compounds (including zirconium dioxide) have been estabHshed by ACGIH. TLV—TWA s are 10 mg/m and 5 mg/m, respectively. OSHA guidelines for zirconium compounds call for a PEL of 5 mg/m. There are no exposure limits for siHcon nitride powder, but pmdent practice suggests a TLV—TWA of 0.1 mg/m. The soHd ceramics present no apparent health hazard. In machining such ceramics, however, care should be taken to prevent inhalation of respirable particles in amounts in excess of estabHshed limits. Disposal should be in approved landfills the materials are inert and should pose no danger to the environment. 

Hafnium dioxide is formed by ignition of hafnium metal, carbide, tetrachloride, sulfide, boride, nitride, or hydrous oxide. Commercial hafnium oxide, the product of the separation process for zirconium and hafnium, contains 97—99% hafnium oxide. Purer forms, up to 99.99%, are available. 

Other Binary Compounds.—Scandium nitride and zirconium and titanium carbide do not conform with the theoretical radii. It is possible that these crystals do not consist essentially of Sc+3, N 3, Ti+4, Zr+4 and C-4 ions, especially since zirconium and titanium nitride, ZrN and TiN, also form crystals with the sodium chloride structure but possibly also the discrepancy can be attributed to deformation of the anions, which have very high mole refraction values. 

---