Boron Nitride
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. Characterization of Different Surface Layers Produced by Solid Boron-Nitro-Carburizing Thermochemical Treatment on AISI 1020
The aim of this study is to obtain and characterize surface layers on low carbon steel with the pack boron-nitro-carburizing process. Different mixtures of commercial powders (Turbonit® and Ekabor®) were used to investigate the case properties, microstructure and phases formation on AISI 1020 steel. A series of experiments were conducted in solid medium wi
Mat. Res.. Publicado em: 04/11/2019
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2. Aplicação da técnica de CAMQL na retificação cilíndrica externa do aço AISI 4340 utilizando rebolo de CBN
RESUMO O processo de retificação possui como características o bom acabamento superficial e alta precisão dimensional e geométrica. Assim, peças usinadas por este processo possuem um alto valor agregado por se tratar de um processo de acabamento que é comumente realizado nas últimas etapas da fabricação. Um fator limitador do processo de retificaç
Matéria (Rio J.). Publicado em: 16/09/2019
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3. Surface Integrity Analisys in the Hard Turning of Cemented Steel AISI 4317
This work was based on the surface integrity analysis of hardened steel, AISI 4317 case carburized, quenched and tempered with 58 HRC, obtained by a turning operation executed with CBN (cubic boron nitride) tool, varying three basic cutting parameters (cutting speed, feed rate and cutting depth). The surface integrity characterization was conducted analyzing
Mat. Res.. Publicado em: 26/07/2018
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4. Evaluation of the oil flow using the MQL technique applied in the cylindrical plunge grinding of AISI 4340 steel with cbn grinding wheel
Abstract The grinding process is defined as an abrasive cutting action of a tool known as grinding wheel, which is submitted to high rotations, promoting excellent finishing and accuracy in dimensions, respecting the parameters established in each project. During the machining, the cutting edges of the abrasive grains undergo wearing and this increases the c
REM, Int. Eng. J.. Publicado em: 2018-07
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5. AVALIAÇÃO DE DIFERENTES ROTAS DE ESFOLIAÇÃO LÍQUIDA PARA OBTENÇÃO DE NANOLAMELAS DE NITRETO DE BORO HEXAGONAL
Hexagonal boron nitride (h-BN), graphite analogous structure, has many interesting applications due to its excellent thermal, electrical and mechanical properties. In this study, different routes of liquid exfoliation using solvent and ultrasound were used to obtain two-dimensional (2D) nanosheets of h-BN. The efficiency of the exfoliative routes was evaluat
Quím. Nova. Publicado em: 2017-09
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6. Investigation on the Effect of Different Pre-Cracking Methods on Fracture Toughness of RT-PMMA
Abstract In this study, eight techniques including coping saw, metal slitting saw, razor blade, cubic boron nitride (CBN) disc, scoring, die-cutting and guillotining, diamond disc, and laser cutting methods were used to produce pre-cracked fracture toughness (Kc) test specimens made of poly(methyl methacrylate)/graft-acrylonitrile butadiene styrene blends. T
Lat. Am. j. solids struct.. Publicado em: 2016-11
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7. Analysis of electronic structure of boron nitride nanotubes with different positions of intrinsic impurities
The pristine boron nitride nanotubes have a large direct band gap around 5 eV. This band gap can be engineered by doping. We investigate electronic structure of the doped hexagonal boron nitride (5,5) nanotubes using the linearized augmented cylindrical wave method. In particular, this work focuses on systematical study of the band gap and the density of sta
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2014-12
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8. Development of self-lubricating composite materials of nickel with molybdenum disulfide, graphite and hexagonal boron nitride processed by powder metallurgy: preliminary study
The purpose of this work was to develop nickel self-lubricating composites using solid lubricant as second phase and obtained by powder metallurgy. The work involved the study of chemical stability and chemical interaction between the nickel alloy matrix and solid lubricating additives (molybdenum disulfide, graphite and hexagonal boron nitride). The results
Mat. Res.. Publicado em: 08/11/2013
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9. Análise de filmes antirreflexo de dióxido de titânio e nitreto de silício em células solares P+NN+
In this work we compared the antireflection coatings of titanium dioxide and silicon nitride for p+nn+ solar cell fabrication. This type of solar cell is more stable in the long term compared to n+pp+ cells and allows obtaining higher efficiencies. TiO2 films were produced by evaporation in high vacuum by electron beam and by chemical vapor deposition at atm
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/12/2012
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10. Fresotorneamento com Ferramentas de cBN do Aço ABNT 8620 Endurecido. / Fresotorneamento with cBN Tools ABNT 8620 Steel Hardened.
A usinagem de materiais endurecidos em substituição à retificação é fator determinante na sobrevivência das corporações quanto à competitividade e manutenção dos principais itens procurados pelo mercado: Preço, Prazo e Qualidade. O Nitreto cúbico de Boro (cBN) tem sido um dos materiais mais utilizados na usinagem de aços endurecidos para acaba
Publicado em: 2011
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11. Nanorolos de nitreto de boro : um estudo por dinamica molecular classica / Boron nitride nanoscrolls : a classical molecular dynamics study
In this work we report a study about the structural and dynamical properties of boron nitride nanoscrolls (BNNSs). BNNSs are nanostructures formed by rolling up boron nitride (BN) sheets into a spiral(papyrus)-like format. Although carbon nanoscrolls (CNSs) have been observed experimentally synthesized using different techniques, up to this moment no experim
Publicado em: 2010
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12. Electronic and structural properties of two mirrored boron-nitride nanocones with 240º disclination
We studied, through first-principles calculations based on the density functional theory, the charge distribution, the density of states and the tip rearrangement of two mirrored boron nitride nanocones with 240 disclination angles and separated from each other from 2 , 3 and 10 under the influence of an external electric field ranging from 0.5 V/ to 1.1 V/
Brazilian Journal of Physics. Publicado em: 2009-04