Navegação IPEN por Autores IPEN "COUTO, ANTONIO A."

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  • IPEN-DOC 27041

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; BRIGUENTE, LUCIANA A.N. da S.; MARCHETTO, LUIZ R.O.; LOPEZ, JAVIER O.. Microstructural evaluation of maraging 300 steel laser treated. In: CONGRESSO BRASILEIRO DE APLICAÇÕES À VACUO NA INDÚSTRIA E NA CIÊNCIA, 38.; WORKSHOP DE TRATAMENTO E MODI CAÇÃO DE SUPERFÍCIES, 3., 21-24 de agosto, 2017, São José dos Campos, SP. Resumo expandido... 2017. p. 46-47.

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  • IPEN-DOC 23991

    MIRANDA, FABIO; RODRIGUES, DANIEL; NAKAMOTO, FRANCISCO Y.; FRAJUCA, CARLOS; SANTOS, GIVANILDO A. dos; COUTO, ANTONIO A. . Microstructural evolution of composite 8 WC-(Co, Ni): effect of the addition of SiC. Defect and Diffusion Forum, v. 371, p. 78-85, 2016. DOI: 10.4028/www.scientific.net/DDF.371.78

    Abstract: Tungsten carbide (WC) based cemented carbides, also called hardmetals, are a family of composite materials consisting of carbide ceramic particles embedded in a metallic binder. They are classified as metal matrix composites (MMCs) because the metallic binder is the matrix that holds the bulk material together [1]. WC based composites are used in applications where a good combination of hardness and toughness are necessary [2]. It is usual to add more components to tailor the microstructure of the WC-(Co, Ni) system. The hardness for the cemented carbides based on nickel, increases significantly because of the addition of reinforcements like SiC nano-whisker [3]. In this work, the SiC was considered as an additional component for the composite WC-8(Co, Ni). Four mixtures were prepared with SiC contents ranging from 0 to 3.0 wt%. These mixtures were pressed (200 MPa) and green samples with 25.2 mm of diameter and 40 g were produced. Sintering was carried out in Sinter-HIP furnace (20 bar). Two sintering temperatures were investigated, i.e. 1380 and 1420ºC, and the sintering time considered was 60 minutes. The relative density, hardness, linear and volumetric shrinkage were determined. Microstructural evaluation was investigated by optical microscopy and scanning electron microscopy (SEM-FEG). The results showed that the addition of SiC promoted higher densification and grain size growth. The hardness was higher for samples with SiC, so solid solution hardening of the binder was more effective than WC grain size growth.

    Palavras-Chave: composite materials; sintering; tungsten carbides; cobalt; nickel; microstructure; metals; hardness

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  • IPEN-DOC 23994

    BALDAN, RENATO; MALAVAZI, JEFFERSON; COUTO, ANTONIO A. . Microstructure and mechanical behavior of Al9Si0.8Fe alloy with different Mn contents. Materials Science and Technology, v. 33, n. 10, p. 1192-1199, 2017. DOI: 10.1080/02670836.2016.1271966

    Abstract: It has been reported that the detrimental effect of Fe on the mechanical properties of Al alloys can be eliminated through the addition of Mn. In this study, we examine the effects of the addition of different Mn contents (0.1, 0.2, 0.4 and 0.7 wt-% of Mn) on the microstructure and mechanical behaviour of Al9Si0.8Fe alloy. It is shown that the presence of up to 0.4 wt-% of Mn changed the platelike morphology of β-Al5FeSi into α-Al15(Fe,Mn)3Si2 with a Chinese script-like morphology. Mn contents higher than 0.4 wt-% promoted the formation of α-Al15(Fe,Mn)3Si2 phase with a polygonal morphology. The effect of the addition of up to 0.7 wt-% of Mn on the mechanical properties of Al9Si0.8Fe alloys is in fact quite negligible.

    Palavras-Chave: aluminium alloys; silicides; iron; casting; mechanical properties; microstructure

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  • IPEN-DOC 22833

    MALAVAZI, JEFFERSON; COUTO, ANTONIO A. ; BALDAN, RENATO; REIS, DANIELI A.P.. Microstructure of the Al-9wt%Si Alloy with Different Fe Contents. In: CONGRESSO BRASILEIRO DE MICROSCOPIA, 25., 7-10 de junho, 2015, Búzios, RJ. Resumo... 2015. p. 387-388.

    Abstract: The Al–Si is the most used cast Al alloy due to their wide application in commercial components. This element strongly reduces the fluidity and the overall mechanical properties through the formation of brittle intermetallic phases. The most common intermetallic is the β-Al5FeSi phase, which generally has a complex plate-like morphology that interrupts the continuity of the matrix, becoming preferential places for crack nucleation and growing. The α-Al8Fe2Si is another intermetallic phase which presents a Chinese script-like morphology. Generally, the α-Al8Fe2Si is less detrimental than β-Al5FeSi phase for the mechanical properties of the alloy owing to its compact morphology. Based on this, the aim of this work is to study the microstructure of the Al-9wt%Si alloy with Fe contents between 0.1 to 1.2 wt%. The chill casting process was chosen due to the higher supercooling of the material during solidification when compared with the sand casting. The material was melted in an induction furnace utilizing a crucible with 30 kg of capacity. The pouring temperature was 760°C. The micrographs were obtained with the aid of a PHILIPS EDAX XL 30 SEM. Figure 1(A) shows the microstructure of the Al-9wt%Si alloy with 0.1 wt% of Fe. It can be seen the Al dendrites and the distribution of the eutectic Si particles with needle shape morphology in the interdendritic regions. Despite the low amount of Fe present in this alloy and the high cooling rate of the chill casting process, it was possible to note the presence of the α-Al8Fe2Si intermetallic phase with Chinese script-like morphology near the eutectic Si particles. Figure 1(B) shows the microstructure of the Al-9wt%Si alloy with 0.4 wt% of Fe. It was possible to note the presence of α-Al8Fe2Si particles with higher amount and size than the alloy with 0.1 wt% of Fe. Figure 2(A) shows the microstructure of the Al-9wt%Si alloy with 0.8 wt% of Fe. It can be seen the Si and β-Al5FeSi particles. Figure 2(B) shows the microstructure of the Al-9wt%Si alloy with 1.2 wt% of Fe. It presents the eutectic Si particles between the arms of Al dendrites and the thick β-Al5FeSi particles formed near the eutectic regions. The high amount and size of β-Al5FeSi particles occurs due to high amount of Fe content. Note that the particles formed by the primary eutectic reaction are bigger that those formed by the secondary eutectic reaction. The sample with 1.2 wt% of Fe presented higher amount of β-Al5FeSi particles than the alloy with 0.8 wt% of Fe and, consequently, higher amount of micropores. Figure 3(A) shows the micropores limited by the β-Al5FeSi particles in the microstructure of the Al-9wt%Si alloy with 0.8 wt% of Fe. This micrograph also shows how β-Al5FeSi platelets constitute potential barriers for liquid metal feeding in a casting region subjected to shrinkage. The amount of β-Al5FeSi phase and, consequently, the amount of micropores is proportional to the Fe content. Figure 3(B) shows the β-Al5FeSi particles formed by the secondary eutectic reaction L→α+Si+ β-Al5FeSi inside a micropore of the Al-9wt%Si alloy with 0.8 wt% of Fe. These particles probably appeared when the vacancies were partially filled with the eutectic liquid and, after the solidification, nucleating and growing along the dendrite ramifications.

    Palavras-Chave: microstructure; aluminium alloys; silicon alloys; mechanical properties; iron; scanning electron microscopy

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  • IPEN-DOC 28570

    MATTOS, MARCIO V.R. de; SANTOS, GIVANILDO A. dos; TERAM, ROGERIO; NASCIMENTO, MAURICIO S. ; SANTOS, VINICIUS T. dos; SILVA, MARCIO R. da; COUTO, ANTONIO A. . Obtenção das variáveis térmicas de solidificação da liga Alpaca 2 c/ Pb: Obtaining the solidification thermal parameters of Alpaca 2 c/Pb alloy. In: INTERNATIONAL CONFERENCE FOR ACADEMIA AND INDUSTRY CO-OPERATION, 2nd; INTERNATIONAL MEETING IN MATERIALS SCIENCE AND ENGINEERING OF MARANHAO, 2nd, November 8-12, 2021, São Luís, MA. Proceedings... 2021. p. 1-7. DOI: 10.29327/2ndicaic2ndimmsem2020.434554

    Abstract: O objetivo deste trabalho é determinar experimentalmente as variáveis térmicas de solidificação da liga Alpaca 2 c/ Pb obtidas após a solidificação unidirecional ascendente do lingote. A liga foi solidificada em uma lingoteira de aço inoxidável AISI 304 montada em um dispositivo de resfriamento unidirecional ascendente. O calor foi extraído direcionalmente através de refrigeração por água na chapa base fabricada em grafite. A microestrutura foi analisada por meio de microscopia óptica (MO). As variáveis térmicas de solidificação velocidade de deslocamento da isoterma liquidus (VL), taxa de resfriamento (TR) e gradiente térmico (GL) foram avaliadas em função da distância da superfície de extração de calor. Como resultado observou-se que maiores taxas de resfriamento e velocidades de deslocamento da isoterma liquidus são obtidas nas posições mais próximas da base de extração de calor.

    Palavras-Chave: ternary alloy systems; solidification; copper alloys; nickel alloys; zinc alloys; castings; thermal analysis

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  • IPEN-DOC 29188

    RIBEIRO, GLEICY de L.X. ; CASTRO, RENATO S. de; PORTO, JOAQUIM F.B.; SILVA, LEANDRO S. da; GABRIEL, ANDRE H.G.; SANTOS, LUIS U. dos; TERADA, MAYSA; OLIVEIRA, RENE ; COUTO, ANTONIO A. . Phases identification and quantification of AISI 316L produced by laser powder bed fusion. In: BRAZIL MRS MEETING, 20th, September 25-29, 2022, Foz do Iguaçu, PR. Abstract... São Carlos, SP: Aptor Software, 2022.

    Abstract: The additive manufacturing process by powder bed fusion (L-PBF) consists of the incidence of a high power laser on the material that promotes the fusion and later the solidification layer by layer creating the 3D from a computational model. The main advantage of this process is the fabrication of objects with complex geometries. AISI 316L steel is widely used in the additive manufacturing process because it has good weldability. Due to good corrosion resistance, it is used as a biomaterial for the manufacture of implants. The high temperatures achieved in the L-PBF process can cause phase transformation, in which part of the austenitic phase (FCC) is transformed into the martensitic phase (CCC), affecting its corrosion resistance. The purpose of this work is the crystallographic characterization by X-ray diffraction of AISI 316L in powder form and after additive manufacturing by L-PBF. The powder used in the process was gas atomized, with an average particle diameter of 50 micrometers. The parts were manufactured using the Yb laser (wavelength 1060 nm) with a scan speed of 1200 mm/s and power of 147 W, 184 W and 211 W. The powder was characterized by SEM for morphological analysis and by X-ray diffraction for phase identification and quantification. The manufactured samples were characterized by SEM and MO, to observe the microstructure, and by X-ray diffraction to identify and quantify the phases present. After the additive manufacturing process, with the increase in laser power, it was possible to observe, in addition to the austenite, the presence of the ferritic phase.

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  • IPEN-DOC 24369

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; OTUBO, JORGE. Short-term creep properties and fracture surface of 18 Ni (300) maraging steel plasma nitrided. Materials Research, p. 1-8, 2017. DOI: 10.1590/1980-5373-mr-2016-0744

    Abstract: Plasma nitriding of a solution annealed and aged 300 grade maraging steel was studied aiming to increase the creep resistance. The surface microhardness reached 1,140 HV, producing 50 μm layer composed of ε-Fe3N and γ’-Fe4N nitrides at the uppermost sample layer. The inner core remained unaltered presenting typical plate-like martensite microstructure of maraging steels with average microhardness of 604 HV. Surface RMS roughness in the nanometric scale increase from 52 nm to 71 nm. The continuous layer of iron nitrides seems to behave as a barrier for oxidation and for inward oxygen diffusion improving the creep resistance by reducing the steady-state creep rate (εs) in 52-65% when compared with the literature results. Dominant creep mechanism is controlled by dislocations climb. Fracture surfaces of specimens presented ductile failure consisting of equiaxed and bi-modal dimples in the fibrous zone surrounded by 45º shear lip. Nitrided sample presented a reduced ductility, associated to the hard surface layer.

    Palavras-Chave: plasma; nitridation; fractures; maraging steels; creep; mechanical properties

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  • IPEN-DOC 26839

    RIBEIRO, ELOANA P. ; FARNEZE, STELLA K. ; COUTO, ANTONIO A. . Shot peening surface treatment effect in 316L stainless steel surface modification. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 216-216.

    Abstract: Stainless steel 316L (low carbon) is the most widely used steel as biomaterial. This metal has low toughness, so metallic implants are prone to wear [1]. Residual compressive stress and surface toughness increase can improve materials life fatigue, as a tough layer prevents plastic deformation. Materials failure, as fatigue and wear, are related to materials surface properties and structure [1]. Shot peening is a mechanical surface treatment in which many small spheres are accelerated and blasted in materials surface to promote impacts with sufficient energy to generate plastic deformation. The main aim of this technique is to induce residual compressive stress on materials surface, increasing wear properties and toughness. Surgical implants are submitted to this treatment to generate surface roughness increase for better adhesion too [2]. In this work, shot peening was performed using four different conditions to verify the effect on surface modification. Microscope techniques, x-ray diffraction, residual stress, toughness and roughness measurements were used to validate the tests. In conclusion, shot peening is an effective surface treatment to induce residual stress and increase roughness and toughness in 316L stainless steel.

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  • IPEN-DOC 23223

    BALDAN, RENATO; SILVA, ANTONIO A.A.P.; NUNES, CARLOS A.; COUTO, ANTONIO A. ; GABRIEL, SINARA B.; ALKMIN, LUCIANO B.. Solution and aging of MAR-M246 nickel-based superalloy. Journal of Materials Engineering and Performance, v. 26, n. 2, p. 465-471, 2017. DOI: 10.1007/s11665-016-2462-0

    Abstract: Solution and aging heat-treatments play a key role for the application of the superalloys. The aim of this work is to evaluate the microstructure of the MAR-M246 nickel-based superalloy solutioned at 1200 and 1250 C for 330 min and aged at 780, 880 and 980 C for 5, 20 and 80 h. The c¢ solvus, solidus and liquidus temperatures were calculated with the aid of the JMatPro software (Ni database). The as-cast and heattreated samples were characterized by SEM/EDS and SEM-FEG. The c¢ size precipitated in the aged samples was measured and compared with JMatPro simulations. The results have shown that the sample solutioned at 1250 C for 330 min showed a very homogeneous c matrix with carbides and cubic c¢ precipitates uniformly distributed. The mean c¢ size of aged samples at 780 and 880 C for 5, 20 and 80 h did not present significant differences when compared to the solutioned sample. However, a significant increasing in the c¢ particles was observed at 980 C, evidenced by the large mean size of these particles after 80 h of aging heat-treatment.

    Palavras-Chave: heat resisting alloys; polycrystals; aging; microstructure; solutions; heat treatments; nickel alloys; hardness

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  • IPEN-DOC 18367

    NEGRETTI, THIAGO B.; KITAGAWA, HELIO; COUTO, ANTONIO A. ; MILETOVIC, CARLOS; PETRUK, ALEX. Structural integrity analysis of the charging air tube support for a diesel engine of commercial vehicle. SAE International, 2012.

    Palavras-Chave: diesel engines; vehicles; mechanical structures; failures; numerical solution; experimental data; dynamic loads

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  • IPEN-DOC 22498

    MARTINS, ANDRE L.T.; COUTO, ANTONIO A. ; LIMA, NELSON B. . Study of the deep drawing behavior and crystallographic texture of AA 3104-H19 aluminum alloy sheets. Proceedings of the Institution of Mechanical Engineers. Proceedings part L, Journal of materials: design and applications, v. 230, n. 3, p. 748-759, 2016.

    Palavras-Chave: aluminium alloys; mechanical properties; texture; strain hardening; strain rate; drawing

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  • IPEN-DOC 23853

    CALIARI, FELIPE R.; CANDIOTO, KATIA C.G.; REIS, DANIELI A.P.; COUTO, ANTONIO A. ; MOURA NETO, CARLOS de; NUNES, CARLOS A.. Study of the mechanical behavior of an Inconel 718 aged superalloy submitted to hot tensile tests. SAE Technical Paper, n. 2011-36-0328, 2011. DOI: 10.4271/2011-36-0328

    Abstract: This study aims to determine some mechanical properties of an Inconel 718 aged superalloy obtained through hot tensile tests. These properties as conventional 0.2% yield strength (σy), ultimate strength (σUTS), and specific elongation assessment (εu) are important parameters in the study of the mechanical material behavior. The superalloy was subjected to hot tensile tests at 650, to 700°C and a strain rate of 0.5 mm/min according to ASTM E-8. It is used a scanning electron microscope (SEM) to obtain images of the fracture surface of the specimens. The images of the fracture surface are analyzed in order to relate the temperature of the test with the type of mechanism of fracture.

    Palavras-Chave: inconel 718; hot cells; tensile properties; fractures; scanning electron microscopy

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  • IPEN-DOC 19541

    CALLIARI, FELIPE R.; GUIMARAES, NARA M.; REIS, DANIELI A.P.; COUTO, ANTONIO A. ; MOURA NETO, CARLOS de; CANDIOTO, KATIA C.G.. Study of the secondary phases in Inconel 718 aged superalloy using thermodynamics modeling. Key Engineering Materials, v. 553, p. 23-28, 2013.

    Palavras-Chave: inconel alloys; heat resisting alloys; hardening; stresses; ruptures; creep; corrosion resistance; microstructure; thermodynamics

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  • IPEN-DOC 21796

    SILVA, LEANDRO C. da; COUTO, ANTONIO A. ; BALDAN, RENATO ; VATAVUK, JAN. Study of the utilization of polyamide composite with fiberglass reinforcement in automotive engine mounts. In: OSCHSNER, A. (Ed.); ALTENBACH, H. (Ed.). Mechanical and materials engineering of modern structure and component design. Switzerland: Springer International Publishing, 2015. p. 71-83, (Advance Structure Materials, 70).

    Palavras-Chave: polyamides; composite materials; fiberglass; fatigue; aluminium; weight; fatigue; automobiles

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  • IPEN-DOC 29888

    MARTINS, ROBERTO F.; FRIEHE, KARL; SILVA, CECILIA C.G. e ; LAZAR, DOLORES R.R. ; COUTO, ANTONIO A. ; LIMA, CARLOS R.C.. Study on the attack of molten silicates on Plasma-Sprayed thermal barrier coatings. Journal of Minerals and Materials Characterization and Engineering, v. 11, n. 5, p. 115-130, 2023. DOI: 10.4236/jmmce.2023.115010

    Abstract: Thermal barrier coating (TBC) revolutionized the industry by allowing higher operating temperatures for equipment, such as gas turbines in the aeronautical industry. However, at high temperatures, the TBC is exposed to the attack of molten silicates, known as CMAS (Calcium-Magnesium-Alumino-Silicate), which are particles from the environment that infiltrate the TBC, causing delamination. In this study, samples coated with TBC by thermal spray and covered with CMAS were evaluated at temperatures of 1200˚C and 1250˚C. For each temperature, exposure times of 1 h and 5 h were used. Samples with longer exposure time had a considerable volume increase. The main contribution of this work was to demonstrate the non-wettability of the CMAS, even in the 5-h heat treatments, which prevented its infiltration in the deeper regions. The conditions to guarantee the formation of the silicate and its consequent wettability are also discussed.

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  • IPEN-DOC 23393

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; SUGAHARA, TARCILA; OTUBO, JORGE. Surface characterization of plasma nitrided maraging 300 steel. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... São Carlos, SP: Aptor Software, 2016. p. 865-865.

    Abstract: Maraging steels belong to a class of high strength steels with the combination of strength and toughness that are among the highest attainable in general engineering alloys. The term maraging is derived from martensite age hardening and denotes the age hardening of a low carbon, iron–nickel lath martensite matrix. These steels typically have very high nickel, cobalt and molybdenum and very low carbon content [1]. For aeronautical components requiring high strength and good wear resistance, such as, slat track, maraging steel possesses high strength, and good wear resistance can be achieved by plasma nitriding process, without sacrificing the strength of the bulk material [2]. In the present work, the surface of maraging 300 steel solution annealed and plasma nitrided was studied by atomic force microscopy (AFM) and microhardness. Samples were solution annealed at 820ºC for 1 h and then plasma nitrided by passing the gas mixture of H2 an N2 gases in the ratio of 3:1 under vacuum and it was carried out at 480ºC for 3 hours. 3D representation of nitrided and un-nitrided samples showed the nitrided samples with peak-valley structure, and the root mean square increase from 52 nm to 73 nm after superficial treatment. Plasma nitriding was effective to increase the microhardness from 331 HV to 1010 HV, and it is associated with the simultaneous aging and the iron nitrides formed.

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  • IPEN-DOC 25833

    CASTRO, MICHELE C.B. de ; COUTO, ANTONIO A. ; ALMEIDA, GISELE F.C. ; MASSI, MARCOS; LIMA, NELSON B. de ; SILVA SOBRINHO, ARGEMIRO da; CASTAGNET, MARIANO ; XAVIER, GLEICY L. ; OLIVEIRA, RENE R. . The effect of plasma nitriding on the fatigue behavior of the Ti-6Al-4V alloy. Materials, v. 12, n. 3, p. 1-13, 2019. DOI: 10.3390/ma12030520

    Abstract: The Ti-6Al-4V alloy is widely used in the manufacture of components that must have low density and high corrosion resistance and fatigue strength. The fatigue strength can be improved by surface modification. The aim of this study was to determine the influence of plasma nitriding on the fatigue behavior of a Ti-6Al-4V alloy with a lamellar microstructure (Widmanstätten type). Nitriding was executed at 720 C for 4 h in an atmosphere with N2, Ar, and H2. Microstructure characterization of the samples was carried out by X-ray diffraction analysis, optical microscopy, and scanning electron microscopy. The average roughness of the specimens was determined, and fatigue tests were executed in a bending–rotating machine with reverse tension cycles (R = 􀀀1). X-ray diffraction analysis of the nitrided alloy revealed the following matrix phases: , , "-Ti2N, and -TiN. A nitrogen diffusion layer was formed between the substrate and the titanium nitrides. Plasma nitriding resulted in an increase in low-cycle fatigue strength, whereas at high cycles of 200 MPa, both conditions exhibited similar behaviors. The fracture surface of the fatigue-tested specimens clearly revealed the lamellar microstructure. The fracture mechanism in the non-nitrided specimens appears to be due to cracking at the interface of the and phases of the lamellar microstructure.

    Palavras-Chave: titanium alloys; aluminium alloys; vanadium alloys; plasma; nitridation; thermochemical processes; fatigue

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  • IPEN-DOC 23394

    RIBEIRO, ALEXANDRE N.; KALLAS, CLAUDETE; SANTOS, GIVANILDO A. dos; NAKAMOTO, FRANCISCO Y.; MORO, JOAO R.; COUTO, ANTONIO A. ; MELO, HERCILIO G. de. The effect of the microstructure upon corrosion resistance of an Al-10wt% Si-2wt%Cu alloy. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... São Carlos, SP: Aptor Software, 2016. p. 1062-1062.

    Abstract: In general, the corrosion behavior strongly depends on the structural morphology and chemical composition. The literature shows relationships between the corrosion behavior and the structural morphology of the secondary dendrite spacing [1]. The objective of this study is to investigate the influence of the microstructure of an Al-10wt%Si-2wt%Cu alloy in its corrosion resistance. In this work, an Al-10wt%Si-2wt%Cu alloy was solidified under upward unsteady state heat flow conditions. Heat was directionally extracted only through a watercooled bottom made of steel (SAE 1020). The aim of the present work is to investigate the influence of the microstructure of this alloy upon corrosion resistance. Experimental results include primary dendrite arm spacings (l1) and capacitances values (ZC P E ). The corrosion behavior was analysed by electrochemical impedance spectroscopy technique conducted in a 3% NaCl solution at room temperature. Coarser dendritic structures tend to improve the corrosion resistance of an Al-10wt%Si-2wt%Cu alloy.

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  • IPEN-DOC 22176

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; MACHADO, JOAO P.. The formation of reverted austenite in 18% Ni 300 grade maraging steel after creep exposure. In: ENCONTRO DA SOCIEDADE BRASILEIRA DE MATERIAIS, 14., September 27 - October 1, 2015, Rio de Janeiro, RJ. Abstract... 2015. p. 1099.

    Palavras-Chave: austenite; maraging steels; x-ray diffraction; optical microscopy; transmission electron microscopy; temperature dependence; time dependence

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  • IPEN-DOC 23395

    RIBEIRO, ALEXANDRE N.; SANTOS, GIVANILDO A. dos; NAKAMOTO, FRANCISCO Y.; KALLAS, CLAUDETE; COUTO, ANTONIO A. ; MELO, HERCILIO G. de; HERNANDEZ, ROCIO D.P.B.. The influence of the microstructure upon corrosion resistance of an Al-10wt% Si-5wt%Cu alloy. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... São Carlos, SP: Aptor Software, 2016. p. 1060-1061.

    Abstract: The need of the industries achieves better specific properties of materials, make to develop studies to meet this demand. For the automotive industry the most interesting properties are low specific weight, low coefficient of thermal expansion, wear resistance at high temperatures and high corrosion resistance. In this context, new materials have been considered, in particular AlSiCu alloys. [1, 2]. In general, the corrosion behavior strongly depends on the structural morphology and chemical composition [3]. In this work, an Al-10wt%Si-5wt%Cu alloy was solidified under upward unsteady state heat flow conditions. Heat was directionally extracted only through a water-cooled bottom made of steel (SAE 1020). The aim of the present work is to investigate the influence of the microstructure of this alloy upon corrosion resistance. Experimental results include primary dendrite arm spacing (l1) and capacitances values (ZCPE). The corrosion behavior was analysed by electrochemical impedance spectroscopy technique conducted in a 3% NaCl solution at room temperature. Coarser dendritic structures tend to improve the corrosion resistance of an Al-10wt%Si-5wt%Cu alloy.

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Ano de publicação: 2015

✔ Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

✔ 95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, bibl@ipen.br .

✔ Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

✔ O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

✔ Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

✔ Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).

ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.