Results 131 to 140 of about 276 (148)

Synthesis of Monodispersed Fine Hafnium Diboride Powders Using Carbo/Borothermal Reduction of Hafnium Dioxide

Journal of the American Ceramic Society, 2008
Fine hafnium diboride (HfB 2 ) powders have been prepared by modified carbothermal/borothermal reduction of hafnium dioxide (HfO 2 ) at relatively low temperatures (1500°–1600°C) for 1–2 h.
De‐Wei Ni, Guo‐Jun Zhang, Yan‐Mei Kan, Pei‐Ling Wang   +3 more
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Special Features of Oxidation of Hafnium Diboride Nanoparticles of Different Dispersity

Russian Journal of General Chemistry, 2018
Products of oxidation of HfB2 particles with mean size 50–55 and 20–25 nm with air oxygen under polythermal and isothermal conditions have been studied by means of thermal analysis, scanning electron microscopy, X-ray energy-dispersive analysis, and elemental analysis. Rate constants of oxidation of the HfB2 nanoparticles have been determined.
A. A. Vinokurov, I. I. Korobov, I. A. Domashnev, N. N. Dremova, A. G. Burlakova, A. V. Ivanov, S. P. Shilkin   +6 more
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Shear strength measurements of hafnium diboride thin solid films

Wear, 2014
Abstract Micromechanical and microscratch properties of chemical vapor deposition synthesized hafnium diboride thin solid films were measured. A range of synthesis conditions was explored by varying the substrate temperature, precursor pressure, and ex situ annealing conditions.
Jungkyu Lee, Kyriaki Polychronopoulou, Andrew N. Cloud, John R. Abelson, Andreas A. Polycarpou   +4 more
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Thermal stability of the phase composition and structure of hafnium diboride films

Inorganic Materials, 2014
The thermal stability of the composition and crystal structure of hafnium diboride films grown by rf magnetron sputtering have been studied by X-ray diffraction and secondary ion mass spectrometry. We have assessed the effect of high-temperature annealing in air on the phase composition and structure of the hafnium diboride films.
A. V. Agulov, A. A. Goncharov, V. A. Stupak, V. V. Petukhov   +3 more
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Abnormal physical behaviors of hafnium diboride under high pressure

Applied Physics Letters, 2019
Hafnium diboride (HfB2) is one of the most promising hard-brittle ceramic materials with unique physical properties. Here, we have synthesized the well-crystallized HfB2 by a high-pressure solid-state reaction and employ in situ high-pressure synchrotron radiation angle-dispersive X-ray diffraction to investigate the size-effect of HfB2.
Hao Liang, Fang Peng, Shixue Guan, Lijie Tan, Haihua Chen, Li Lei, Duanwei He, Cheng Lu   +7 more
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Special features of preparation of nanosized hafnium diboride of different dispersity

Russian Journal of General Chemistry, 2015
X-ray diffraction analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry, and elemental analysis have been applied to study the products of interaction of powder hafnium with fine-crystalline boron in the Na2B4O7 ionic melt at 600–850°C and of HfCl4 with NaBH4 at 300–700°C.
S. E. Kravchenko, A. G. Burlakova, Yu. M. Shulga, I. I. Korobov, I. A. Domashnev, N. N. Dremova, G. V. Kalinnikov, S. P. Shilkin, R. A. Andrievskii   +8 more
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Size effect on the structure of nanocrystalline and cluster films of hafnium diboride

The Physics of Metals and Metallography, 2009
Hafnium diboride films have been obtained by the method of nonreactive hf magnetron sputtering in an argon atmosphere. It has been shown that the determining role in the processes of the formation of the structure of these films belongs to the size effect.
A. A. Goncharov, V. A. Konovalov, G. K. Volkova, V. A. Stupak   +3 more
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Effect of Antimony on the Reaction of Hafnium Diboride with Iridium

Russian Journal of Inorganic Chemistry, 2022
V. V. Lozanov, N. I. Baklanova, D. A. Bannykh, A. T. Titov   +3 more
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SYNTHESIS OF CERAMIC POWDERS OF HAFNIUM DIBORIDE BY CARBOTHERMAL RESTORATION METHOD

Steklo i Keramika
The processes of obtaining hafnium diboride by the carbothermic reduction of hafnium oxide by heat treatment in a vacuum furnace and a spark plasma sintering installation have been studied. When the charge was heat treated in a vacuum furnace, hafnium diboride powder was obtained in the temperature range 1500...1700 °C, but it is characterized by the ...
N. E. Shchegoleva, Yu. E. Lebedeva, S. G. Kolyshev, M. L. Vaganova, A. S. Chainikova   +4 more
openaire   +1 more source

Hot pressing of hafnium diboride aided by different sinter additives

Journal of Materials Science, 2007
Experiments were conducted by hot-pressing to densify HfB2 commercial powders using HfSi2 (5 vol%) or B4C (7 vol%) as sinter additives. The former was very effective as sintering enhancer: 15 min at 1,600°C was a sufficient condition to achieve near full density.
openaire   +2 more sources