Nitriding
Mostrando 1-12 de 96 artigos, teses e dissertações.
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1. Nitretação por descargas elétricas da liga Ti-6Al-4V com adição de pó abrasivo SiC ao fluido dielétrico
RESUMO O processo de nitretação que usa Usinagem por Descargas Elétricas é um método que associa a capacidade de usinar superfícies complexas com a obtenção de tratamento termoquímico de nitretação. A fonte de nitrogênio é proveniente da uréia, que compõe o fluido dielétrico juntamente com água deionizada. A liga de titânio Ti-6Al-4V possui
Matéria (Rio J.). Publicado em: 16/09/2019
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2. Effects of Gas Nitriding on Fatigue and Crack Initiation of Ti6Al4V produced by Selective Laser Melting
Selective laser melting (SLM) is an additive manufacturing technique which permits fabrication of three dimensional parts by selectively melting consecutive layers of metallic powder. This allows the production of parts with high geometrical complexity. Titanium alloy Ti-6Al-4V (Ti64) is widely used in industry due to its high strength-to-mass ratio, corrosi
Mat. Res.. Publicado em: 15/07/2019
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3. Influence of the Gas Pressure of Plasma Nitriding on the Structural, Mechanical and Tribological Surface Properties of AISI 316L
In this paper, the influence of gas nitriding (80% H2-20% N2) pressure (between 3 and 7 Torr) on the modification of surface properties of AISI 316L stainless steel is examined. The structural, mechanical, tribological and electrochemical properties of the layer produced in disk samples were studied. The samples’ characteristics were determined by scanning
Mat. Res.. Publicado em: 15/07/2019
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4. Changing the characteristics of the nitrided layer using three different plasma configurations
ABSTRACT Direct current (DC) plasma nitriding offers some disadvantages, especially in parts with complex geometries, where the presence of edges is significant, such as gears, molds, and needle punched parts are strongly affected by this effect, leading to irregular formation of nitrided layers and high variation in surface hardness. To solve these problems
Matéria (Rio J.). Publicado em: 10/06/2019
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5. Obtenção de austenita expandida (fase S): Nitretação por plasma em baixa temperatura x SHTPN – Parte 3
RESUMO Corpos de prova de aço inoxidável austenítico ISO 5832-1(similar ao AISI 316L, para aplicações biomédicas) apresentando camada superficial enrriquecida em nitrogênio (fase S), obtidos pelos processos de nitretação por plasma em baixa temperatura e SHTPN (Solution Heat Treatment after Plasma Nitriding -Tratamento de solubilização após nitre
Matéria (Rio J.). Publicado em: 20/05/2019
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6. The influence of nitrogen to hydrogen ratio and temperature on thickness and phase composition in plasma nitrided Ti-6Al-4V
ABSTRACT Ti-6Al-4V was plasma nitrided using several N2/H2 ratios and substrate temperatures. In order to investigate the combined influence of these parameters on phase composition and thickness of the coatings, the phases in the as received, annealed, and nitrided Ti-6Al-4V samples were identified with Rietveld refinement. In the as-received and annealed s
Matéria (Rio J.). Publicado em: 20/05/2019
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7. Enhancement of Pitting Corrosion Resistance of Austenitic Stainless Steel Through Deposition of Amorphous/Nanocrystalline Oxy-nitrided Phases by Active Screen Plasma Treatment
In this research, AISI 304 austenitic stainless steels were efficient treatment using active screen plasma oxy-nitriding technique. The modified layers were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopes, and atomic force microscopy. In addition, the pitting corrosion resi
Mat. Res.. Publicado em: 29/10/2018
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8. Extensión de durabilidad de pistones de bombas de fractura hidráulica mediante el empleo de tecnología de nitruración por plasma y PVD
ABSTRACT Hydraulic stimulation technique consists of "fracturing" the formation (rock reservoirs) through pumping a fracturing fluid downhole. This operation is performed by using hydraulic fracturing pumps. The pistons of these pumps are mechanical components performing the intake and compressing fracture fluid by reciprocating action. During this alternati
Matéria (Rio J.). Publicado em: 19/07/2018
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9. Protección de acero para instrumentos quirúrgicos con recubrimientos duros en base carbono tipo DLC
ABSTRACT Martensitic stainless steels can be used in different applications such as surgical instruments where a good wear and corrosion resistance are required. Surface modification treatments such as nitriding improve the mechanical properties of these steels, however; they affect the corrosion resistance. For this reason, the DLC (Diamond Like Carbon) coa
Matéria (Rio J.). Publicado em: 19/07/2018
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10. Mass Spectrometry Study of Ammonia Formed During Plasma Nitrocarburizing and Nitriding Processes
In this work, we used mass spectrometry to investigate ammonia (NH3) formed during the nitrocarburizing and nitriding processes of α-Fe sintered and low alloy steel by using d.c. glow discharges in different N2/H2/CH4 gas concentration mixtures. Experiments were conducted using two different configurations: one to collect and analyze species probed primaril
Mat. Res.. Publicado em: 16/07/2018
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11. Corrosion Behavior of Plasma Nitrided and Nitrocarburised Supermartensitic Stainless Steel
Supermartensitic stainles steels (SMSS's) are a new generation of martensitic steels that have been increasingly used in oil and gas applications due to their adequate corrosion resistance and mechanical properties. In the present study, SMSS specimens (UNS S41425) were solution heat treated and air cooled followed by plasma nitriding and nitrocarburising at
Mat. Res.. Publicado em: 12/03/2018
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12. Synthesis of Gallium Nitride and Related Oxides Via Ammonobasic Reactive Sublimation (ARS)
Ammonobasic reactive sublimation (ARS) is proposed as a novel method to synthesize GaN and related oxides. Results indicate that GaN growth occurs by a nitriding process of Ga and related oxides, establishing a direct dependence on NH4OH amount added as a primary chemical reactive. The samples were grown on p-type Si (111) substrates inside a tube furnace, e
Mat. Res.. Publicado em: 28/09/2017