Results 21 to 30 of about 20,006 (235)

Phase boundary between Na-Si clathrates of structures I and II at high pressures and high temperatures [PDF]

, 2016
Understanding the covalent clathrate formation is a crucial point for the design of new superhard materials with intrinsic coupling of superhardness and metallic conductivity.
Godec, Yann Le, Guignot, Nicolas, Jouini, Zied, Kurakevych, Oleksandr O., Mezouar, Mohamed, Moutaabbid, Hicham   +5 more
core   +3 more sources

Hard machining of agricultural machines parts

Research in Agricultural Engineering, 2013
For the renovation and/or improvement of the surface properties of machine elements, hard facing is often used. Hard structures obtained in layers or by heat treatment achieve a hardness of up to 68 hardness (HRC) or even more.
R. Drlička, J. Žarnovský, R. Mikuš, I. Kováč, M. Korenko   +4 more
doaj   +1 more source

Synthesis of cBN-hBN-SiC_w Nanocomposite with Superior Hardness, Strength, and Toughness

Nanomaterials, 2022
Nanocomposites with one-dimensional (1D) and two-dimensional (2D) phases can demonstrate superior hardness, fracture toughness, and flexural strength. Cubic boron nitride-hexagonal boron nitride-silicon carbide whiskers (cBN-hBN-SiCw) nanocomposites with
Lei Sun, Yitong Zou, Mengdong Ma, Guangqian Li, Xiaoyu Wang, Xiang Zhang, Zewen Zhuge, Bing Liu, Yingju Wu, Baozhong Li, Zhisheng Zhao   +10 more
doaj   +1 more source

Ab-initio calculations of carbon and boron nitride allotropes and their structural phase transitions using periodic coupled cluster theory

, 2018
We present an ab-initio study of boron nitride as well as carbon allotropes. Their relative thermodynamic stabilities and structural phase transitions from low- to high-density phases are investigated.
Gruber, Thomas, Grüneis, Andreas
core   +1 more source

Physics and chemistry of hydrogen in the vacancies of semiconductors [PDF]

, 2003
Hydrogen is well known to cause electrical passivation of lattice vacancies in semiconductors. This effect follows from the chemical passivation of the dangling bonds.
A. Fara, A. Gali, A. Zywietz, Adam Gali, B. Aradi, Bernadett Szûcs, C. G. Van de Walle, C. G. Van de Walle, C. Stampfl, Chris G. Van de Walle, D. M. Ceperley, G. A. Baraff, G. Makov, H. J. Monkhorst, H.-U. Baier, I. Gorczyca, I. Jiménez, J. Lu, J. Neugebauer, J. Neugebauer, J. P. Perdew, J.N. Russell, Jr., L. J. Schowalter, M. Bockstedte, M. Fanciulli, M. Yeadon, N. Troullier, P. Piquini, Peter Deák, T. Mattila, V. A. Gubanov, W. Kohn, W. Orellana, W. Orellana, Zoltán Hajnal   +34 more
core   +1 more source

Synthesis of Cubic Boron Nitride

Journal of the Ceramic Association, Japan, 1970
Cu5Sn, Cu5Sn8,Mg9Sn91合金あるいは Mg 金属の1部と, 六方晶 BN の4部の混合物を白金チューブに充填し, 改良ガードル型高圧装置を用いて, 最大約 80kbar, 2200℃, 30分間の条件下で処理した。不純物を酸で分離後, 合成立方晶 BN をデバイ・シェラーX線回折図形, 硬度試験などで同定した。例えば Cu5Sn 合金の場合, zinc-blende 構造をもつ立方晶 BN を約 1000℃, 40kbarの条件下で合成した。結晶の大きさは数0～ 数100μ であり,色相は灰色,暗黒色,白色などであった。六方晶〓立方晶 BN 平衡線は Wentorf の実験的平衡1線の延長上に存在した。Mg9Sn91合金と Mg 金属の場合, おのおの約 1000℃, 32kbar,
Masumi USHIO, Hajime SAITO, Shuichi NAGAO   +2 more
openaire   +2 more sources

HETERO-GRAPHENE AND HETERO-DIAMOND PHASES SYNTHESIZED IN THE B-C-N SYSTEM UNDER PRESSURE [PDF]

Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов, 2013
The phases formation in the B-C-N system at thermobaric treatment of mixtures of carbon nitride or melamine with boron has been studied. It was found that in the pressure range of 4-8 GPa graphite-like particles were formed first.
V.P. Filonenko, I.P. Zibrov, V.A. Sidorov, M.V. Trenihin   +3 more
doaj  

Anisotropic Dielectric Breakdown Strength of Single Crystal Hexagonal Boron Nitride

, 2016
Dielectric breakdown has historically been of great interest from the perspectives of fundamental physics and electrical reliability. However, to date, the anisotropy in the dielectric breakdown has not been discussed.
Hattori, Yoshiaki, Nagashio, Kosuke, Taniguchi, Takashi, Watanabe, Kenji   +3 more
core   +2 more sources

On the cutting force of micro-textured polycrystalline cubic boron nitride cutting tool for powder metallurgy materials

Advances in Mechanical Engineering, 2020
Micro-textured cutting tools were widely reported due to the improved cutting performance, for example, the reduction of cutting forces. However, the cutting performance is significantly dependent on the parameters of the micro-textures.
Haidong Yang, Zhengguang Han, Xiquan Xia, Qidong Wang, Juchen Zhang, Weijie Chang, Zhenhua Qing, Huohong Tang, Shunhua Chen   +8 more
doaj   +1 more source

Low pressure growth of cubic boron nitride films [PDF]

, 1997
A method for forming thin films of cubic boron nitride on substrates at low pressures and temperatures. A substrate is first coated with polycrystalline diamond to provide a uniform surface upon which cubic boron nitride can be deposited by chemical ...
Ong, Tiong P., Shing, Yuh-Han
core   +1 more source