Carbides carbonitrides

AH of the alloys Hsted in Tables 4 and 5 are austenitic, ie, fee. Apart from and soHd-solution strengthening, many alloys benefit from the presence of carbides, carbonitrides, and borides. Generally the cubic MC-type monocarbides, which tend to form in the melt, are large and widely spaced, and do not contribute to strengthening. However, the formation, distribution, and soHd-state reactions of carbides are very important because of their role... 

Over a decade, Bandi and co-workers have employed EGA-DTA techniques to determine second-phase compounds isolated from steels by selective chemical or anodic dissolution of the matrix. This method has been used qualitatively to identify and quantitatively to determine approximately 35 carbides, carbonitrides, and nitrides, some of which could not be identified... 

The latest patent applications try to obtain more fine grained microstructures outside the known compositions Al203/TiC or Al203/Ti(C,N). An alumina composite with 25% (by weight) of a mixed carbide/carbonitride consisting of about 90% Ti(C,N) and 10% WC was hot pressed at 1600°C yielding a microstructure with... 

Nitrogen and carbon are the most potent solutes to obtain high strength in refractory metals (55). Particulady effective ate carbides and carbonitrides of hafnium in tungsten, niobium, and tantalum alloys, and carbides of titanium and zirconium in molybdenum alloys. 

Ferritic Nitrocarburizing. This process is similar to carbonitriding, except that it is carried out in the temperature range of the stabiHty of ferrite and carbide (<723° C). Therefore hardening is not by martensite formation, but because of the formation of very hard carbonitrides. 

The first carbonitride alloys based on Ti(C,N)—Ni—Mo were iatroduced ia 1970 foUowed by (Ti, Mo)(C,N)-based compositions having fine microstmctures that provided a balance of wear resistance and toughness (4). Continued research on the titanium carbonitride alloys, often called TiC—TiN cermets, ia the 1980s led to the developmeat of complex cermets having a variety of additives such as molybdeaum carbide(2 l) [12069-89-5] M02C, TaC, NbC, zirconium carbide [12020-14-3], ZrC, hafnium carbide [12069-85-1], HfC, WC, vanadium carbide [12070-10-9], VC, chromium carbide (3 2)... 

Molybdenum carbide is also used in TiC—Ni-based alloys and in titanium carbonitride-based cermets for metal-cutting appHcations. 

Kohlenstoff-hydrat, n. carbohydrate, -kalium, n. potassium carbide, -kem, m. carbon nucleus. -kette,/. carbon chain, -legiening,/, carbon alloy, -metall, n. carbide, kohlenstoffrelch, a. rich in carbon. Kohlenstoff-silicium, n. carbon silicide. -ske-lett, n. carbon skeleton, -stahl, m. carbon steel, -stein, m. carbon brick, -sticlKtoff-titan, n. titanium carbonitride. -sulfid, n. 

An extension of the reduction-chlorination technique described so far, wherein reduction and chlorination occur simultaneously, is a process in which the oxide is first reduced and then chlorinated. This technique is particularly useful for chlorinating minerals which contain silica. The chlorination of silica (Si02) by chlorine, in the presence of carbon, occurs above about 1200 °C. However, the silica present in the silicate minerals readily undergoes chlorination at 800 °C. This reaction is undesirable because large amounts of chlorine are wasted to remove silica as silicon tetrachloride. Silica is, therefore, removed by other methods, as described below, before chlorination. Zircon, a typical silicate mineral, is heated with carbon in an electric furnace to form crude zirconium carbide or carbonitride. During this treatment, the silicon in the mineral escapes as the volatile oxide, silicon monoxide. This vapor, on contact with air, oxidizes to silica, which collects as a fine powder in the furnace off-gas handling system ... 

Boron-containing nonoxide amorphous or crystalline advanced ceramics, including boron nitride (BN), boron carbide (B4C), boron carbonitride (B/C/N), and boron silicon carbonitride Si/B/C/N, can be prepared via the preceramic polymers route called the polymer-derived ceramics (PDCs) route, using convenient thermal and chemical processes. Because the preparation of BN has been the most in demand and widespread boron-based material during the past two decades, this chapter provides an overview of the conversion of boron- and nitrogen-containing polymers into advanced BN materials. 

Summary A brief review of the preparation of silicon containing preceramic polymers to prepare silicon carbide and silicon carbonitride fibers is given. Methylchlorodisilanes are converted to polysilanes and polysilazanes which yield ceramic fibers after meltspinning, curing, and pyrolysis. 

The Miiller-Rochow-Synthesis [16,17] (direct synthesis of methylchlorosilanes) provides as byproduct a high boiling fraction consisting essentially of 1,1,2-trimethyltrichlorodisilane and 1,2-dimethyltetrachlorodisilane [18]. Starting with these disilanes Wacker-Chemie has developed different ways to produce silicon carbide [19, 21] and silicon carbonitride [22] fibers. 

Cobalt Carbonitrides, Co2(C, N), and of Cobalt Carbide, Co2C. Chem. week 68, 1004 (1951)-... 

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... 

Nitride Coatings. Carbide tips coated with titanium nitride or titanium carbonitride are usually manufactured by a CVD process using T1CI4, H4, and N2 in a hot-wall reactor. 

Examples of products made by the SHS process include borides, carbides, chalcogenides, hydrides, intermelallic compounds, nitrides, silicides, carbonitrides, sulfides, cemented carbides (cermets), and various heterogeneous mixtures (microcomposiles). 

Chemical vapor deposition is used industrially to deposit protective hard coatings on metal objects. Common coatings are titanium carbide (TiC), titanium nitride (TiN), titanium oxycarbide (TiCxOy), titanium carbonitride (TiCxNy), titanium oxycarbonitride (TiCxNyOz).91 Coatings based on TiC... 

Carbides and nitrides based on the transition metals of Groups 4 through 6 of the Periodic Table have a number of special physical and mechanical properties that make them attractive for use in engineering applications. This paper discusses these properties and how they are exploited in cemented carbides and carbonitrides used in metalcutting and nonmetalcutting applications. 

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