Phase diagram carbon-boron

The europium-boron-carbon phase diagram. The ternary system Eu-B-C has been studied, with special emphasis on the technologically important sections EuBg-C and EUB6-B4C (Schwetz et al. 1979). Samples were synthesized from the pure elements at 1500°C in sealed molybdenum capsules and annealed for 20 h. The X-ray diffraction pattern of EUB2C2 has been indexed on the basis of a tetragonal unit cell with a = 3.77 A and c = 4.03 A. 

The gadolinium-boron-carbon phase diagram. The Gd-B-C system in the range 2000-3000°C was determined (Smith and Gilles 1967, fig. 18). The upper portion of this diagram is less well-established than the lower part. This diagram shows only the approximate composition of the phases and does not necessarily show... 

Figure 4.4 The boron-carbon phase diagram according to Schwetz and Karduck [25],...

Rogl, P. and G. Eftenberg Phase Diagrams of Ternary Metal-Boron-Carbon Systems, ASM International, Materials Park, OH. 1998. 

Boron carbide is rhombohedral (a = 5.163 A a = 65.59°). The stoichiometric composition of boron carbide is Bi3C2(B6.5C), so that B4C is a carbon-saturated solid solution. The phase diagram for the B-C system is shown in Figure 1. The density as a function of stoichiometry is shown in Figure 2. 

E. Rudy, Ternary phase equilibria in transition metal-boron-carbon-silicon systems. Part V. Compendium of phase diagram data. Tech. Rep. AFML-TR—Air Force Mater. Lab. (US.) AFML-TR-65-2 (1969). 

Starting from fine boron and carbon powders, the direct synthesis of stoichiometric boron carbide is possible -, either under vacuum at 2073K in an electric furnace, or at 2273 K by hot pressing under Ar. This method is inefficient economically and finds no practical application. The compositions in the phase homogeneity range B10.4C-B4C can be obtained by hot pressing mixtures of B C with boron . The diffusion diagram between B and C is established. ... 

Although only a few phase diagrams of the R-boron-carbon systems [R = Y (Bauer and Nowotny 1971), Eu (Schwetz et al. 1979), Gd (Smith and Grilles 1967), and Ho (Bauer et al. 1985)] have been published, several studies on the formation of the... 

Along the EUB6-B4C section again the formation of the solid solution EuBg- Q occurs, but no ternary compound was found. The isothermal section of the tentative phase diagram of the europium-boron-carbon system at 1500°C has been deduced (see fig. 17). To give a better overview, the Eu(B, C)g and i2+xCz-x solid solution has not been included within the diagram. 

Rudy, E. Ternary Phase Equilibria in Transition Metal-Boron-Carbon-Silicon Systems, Vol. V, Compendium of Diagram Data, US Atomic Energy Comm. Publ. AFML-TR-65-2, Wright Patterson Air Force Base, OH, 1969. 

Sop] Sopousek, J., Vrestal, J., Phase Equihbria in the Fe-Cr-Ni and Fe-Cr-C Systems , Z. Metallkd., 85(2), 111-115 (1994) (Morphology, Phase Diagram, Experimental, 20) [1994Wit] Witusiewicz, V.T., Thermodynamic Properties of Liquid Alloys of 3d Transition Metals with Metalloids (Sihcon, Carbon and Boron) , J. Alloys Compd., 203, 103-116 (1994) (Thermodyn., Experimental, Review, 89)... 

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