Results 231 to 240 of about 9,993 (282)

Phosphorus doping of boron carbides

Physical Review B, 1993
Substitution of an electron donor such as phosphorus for a carbon or boron atom in [ital p]-type semiconducting boron carbides is expected to reduce the hole concentration. Phosphorus-doped boron carbide samples have been prepared by hot isostatic pressing with homogeneous dopant levels of up to one phosphorus atom per ten unit cells.
, Aselage, , Emin, , Samara, , Tallant, , Van Deusen SB, , Eatough, , Tardy, , Venturini, , Johnson   +8 more
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The melting of boron carbide and the homogeneity range of the boron carbide phase

Journal of the Less Common Metals, 1979
Abstract Various mixtures of boron and carbon were electron beam melted. The samples were characterized by electron microprobe analysis, metallographic techniques, X-ray diffraction and Knoop microhardness measurements. The metallographic investigations, together with the electron microprobe phase analysis, showed that the boron carbide phase exists ...
M Bouchacourt, F Thevenot
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Pressureless sintering of titanium carbide doped with boron or boron carbide

Journal of the European Ceramic Society, 2017
Abstract Titanium carbide ceramics with different contents of boron or B 4 C were pressureless sintered at temperatures from 2100 °C to 2300 °C. Due to the removal of oxide impurities, the onset temperature for TiC grain growth was lowered to 2100 °C and near fully dense (>98%) TiC ceramics were obtained at 2200 °C.
Yifeng Gu, Ji-Xuan Liu, Fangfang Xu, Guo-Jun Zhang   +3 more
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Ternary Metal Boron Carbides

International Journal of Refractory Metals and Hard Materials, 1999
Based on a simple principle of order: i.e. the ability of the metal species to form or not to form binary bondes, binary carbides and ternary compounds, phase equilibria of all hitherto known ternary metal boron systems are classified by four major categories. Compound formation is generally observed with rather electropositive metal elements.
P. Rogl, H. Bittermann
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Thermal expansion of boron and boron carbide

Journal of the Less Common Metals, 1986
Abstract Thermal expansion of poly crystalline α-rhombohedral boron (in the range from 300 to 1270 K), of β-rhombohedral boron (from 300 to 1470 K) and boron carbide B 4 C (from 300 to 1970 K) have been investigated by means of high temperature X-ray diffractometry. The linear coefficients of thermal expansion perpendicular ( α ⊥ ) and parallel ( α
G.V Tsagareishvili, T.G Nakashidze, J.Sh Jobava, G.P Lomidze, D.E Khulelidze, D.Sh Tsagareishvili, O.A Tsagareishvili   +6 more
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Sputtering behavior of boron and boron carbide

Journal of Nuclear Materials, 1992
Sputtering yields of boron were measured with D + and B + ions for normal and oblique angles of incidence. Self-sputtering data of boron carbide were simulated in the experiment by using Ne + ions. The energies of the impinging ions were between 20 eV and 10 keV.
Hechtl, E., Mazanec, A., Eckstein, W., Roth, J., Garcia-Rosales, C.   +4 more
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Thermal properties of boron and boron carbides

AIP Conference Proceedings, 1986
The specific heat of β‐B shows the features characteristic for pure dielectric crystals. At low temperatures, it varies as T3; from the prefactor the Debye temperature is determined to 1520 K. In boron carbides, however, low temperature anomalies have been observed.
P. R. H. Türkes, E. T. Swartz, R. O. Pohl   +2 more
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Effect of Boron, Boron Carbide and Alumina Additions on the Sintering of Silicon Carbide

Transactions of the Indian Ceramic Society, 1990
The effect of boron, boron carbide and alumina, all with carbon additions, on the sintering behaviour of silicon carbide powders obtained by silicon-carbon reaction and silica-carbon reaction was investigated. The concentrations of these additives—B, B4C, Al2O3, C—were varied up to 5 wt%.
S. Ramanatahan, Ram Prasad, C. K. Gupta
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Processing of silicon carbide–boron carbide–aluminium composites

Journal of the European Ceramic Society, 2009
Abstract The aim of this work was to shed light on the wetting mechanism in the SiC–B 4 C–Al system and to explore processing routes that enable infiltration of Al alloys into these ceramic powder mixtures without the formation of the deleterious reaction product Al 4 C 3 .
Arslan, Gürsoy, Kalemtaş, Ayşe
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Voids in boron carbide

Journal of Nuclear Materials, 1973
Abstract Two different void morphologies have been observed in the commercial grades of boron carbide that are currently undergoing assessment as candidates for the control rod material in fast breeder reactors. Some grains in unirradiated powders contain dodecahedral voids which are closely associated with iron-rich precipitates believed to be ...
K.H.G. Ashbee, F.C. Frank, C.K.H. DuBose
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