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Behaviour of biofuel addition on metallurgical properties of sinter

SILVA, S. N.; VERNILLI, F.; PINATTI, D. G.; NASCIMENTO, V. F. do; SAITO, E.; CANGANI, M. P.; NEVES, E. S.; LONGO, E.
Fonte: MANEY PUBLISHING Publicador: MANEY PUBLISHING
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
516.26496%
Blast furnace gas yield is essentially controlled by a gas-solid reaction phenomenon, which strongly influences hot metal manufacturing costs. As a result of rising prices for reducing agents on the international market, Companhia Siderurgica Nacional decided to inject natural gas into its blast furnaces. With more gas inside the furnace, the burden permeability became even more critical. To improve blast furnace gas yield, a new technological approach was adopted; raising the metallic burden reaction surface. To that end, a special sinter was developed with permeability being controlled by adding micropore nucleus forming agents, cellulignin coal, without, however, degrading its mechanical properties. This paper shows the main process parameters and the results from physicochemical characterisation of a sinter with controlled permeability, on a pilot scale, compared to those of conventional sinter. Gas flow laboratory simulations have conclusively corroborated the positive effects of micropore nucleus forming agents on enhancing sinter permeability.

Modification of surface properties of Ti-16Si-4B powder alloy by plasma immersion ion implantation

FERNANDES, Bruno Bacci; UEDA, Mario; MELLO, Carina Barros; FERNANDES, Paulino Bacci; REUTHER, Helfriecl; RAMOS, Alfeu Saraiva
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
414.6508%
Results of the surface modification of Ti-16Si-4B powder alloy by nitrogen ion implantation are presented, together with the experimental description of the preparation of that powder by high-energy ball milling and hot pressing. The phase structure, chemical composition and morphology of sample surfaces were observed by utilizing X-ray diffractometer (XRD), atomic force microscope (AFM) and scanning electron microscopy (SEM). A tribological characterization was carried out with a ball-on-disc tribometer and an SEM. Friction coefficient is compared with the one obtained for Ti-6Al-4V alloy and the wear scars characterized by SEM/EDS (energy dispersive spectroscopy). The concentration profile of the detected elements have been investigated using Auger electron spectroscopy (AES) depth profiling. Our results show that a shallow implanted layer of oxygen and nitrogen ions were obtained at the Ti-16Si -4B alloy surface, sufficient to modify slightly its tribological properties. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.; FAPESP; Sao Paulo State; CNPq (National Council of Research and Development)

Equivalence between hot tensile and creep testing data for Kanthal A1 alloy

MORETO, Jéferson Aparecido; CASTRO, Danilo Borges Villarino de; BUENO, Levi de Oliveira; PONTE, Haroldo de Araujo
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
Hot tensile and creep tests were carried out on Kanthal A1 alloy in the temperature range from 600 to 800 degrees C. Each of these sets of data were analyzed separately according to their own methodologies, but an attempt was made to find a correlation between them. A new criterion proposed for converting hot tensile data to creep data, makes possible the analysis of the two kinds of results according to usual creep relations like: Norton, Monkman-Grant, Larson-Miller and others. The remarkable compatibility verified between both sets of data by this procedure strongly suggests that hot tensile data can be converted to creep data and vice-versa for Kanthal A1 alloy, as verified previously for other metallic materials.

Design of concrete-filled steel tubular columns under axial loading according to NBR 8800:2008 and Eurocode 4:2004: tests results and comparisons

OLIVEIRA, Walter Luiz Andrade de; NARDIN, Silvana De; DEBS, Ana Lucia H. de C. El
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
In this paper results of tests on 32 concrete-filled steel tubular columns under axial load are reported. The test parameters were the concrete compressive strength, the column slenderness (L/D) and the wall thickness (t). The test results were compared with predictions from the codes NBR 8800:2008 and EN 1994-1-1:2004 (EC4). The columns were 3, 5, 7 and 10 length to diameter ratios (L/D) and were tested with 30MPa, 60MPa, 80MPa and 100MPa concrete compressive strengths. The results of ultimate strength predicted by codes showed good agreement with experimental results. The results of NBR 8800 code were the most conservative and the EC4 showed the best results, in mean, but it was not conservative for usual concrete-filled short columns.

Contribution of headed studs to the composite behavior of the partially encased beams

NARDIN, Silvana De; DEBS, Ana Lucia H. de C. El
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
The use of mechanical shear connectors, mainly headed stud bolts, is the most common way to achieve steel-concrete composite action. The encasement of the steel beam in the depth slab results in increase of strength and stiffness, reducing the total height of the floor. In this investigation, three partially encased composite beams were tested under flexural conditions and the main objective was to investigate some alternative positions for the headed studs. To provide longitudinal shear resistance between the I-shaped beam and the concrete, two positions of the,studs were investigated: vertically welded on the bottom flange and horizontally welded on the faces of the web. The experimental results have shown that the headed studs are effective to provide the composite action and increase the bending strength. Furthermore, the headed studs welded vertically on the bottom flange proved to be the most reliable position.

Sorption aspects for unconsolidated materials of the Sao Carlos region (SP), Brazil

ZUQUETTE, Lazaro Valentin; SILVA JR., Everaldo M.; GARCIA, Antonio
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
The transport of liquid and gaseous pollutants through porous geological media depends on the physical and chemical characteristics of the unconsolidated material, rocks and water associated with the characteristics of the pollutants. Of these characteristics, the sorption aspect is of fundamental importance and is a function of the mineral proportions, pH, Eh and void aspects encountered in the porous media. In the Sao Carlos region, located in the eastern-central part of the 9 ate of Sao Paulo, Brazil, there are basically two types of unconsolidated materials: the first is a residual from sandstones cemented with fines and the secondarily composed of claystones, siltstones and conglomerates from the Cretaceous Period that constitute the Itaqueri Formation; the second is a sandy sediment of the Tertiary Period. These geological conditions are found in areas where chemical products are disposed of characterized as either diffuse or point pollutions sources. Because of this situation, a study was developed to evaluate the sorption aspects of some inorganic cations that are frequently found in these sources, in varied concentrations. Taken into consideration were their physical/chemical properties, such as: specific weight, grain size...

Quality of martensitic stainless steel type AISI-420 utilized in the manufacture surgical implements

RODRIGUES, Cesar Augusto Duarte; ENOKIBARA, Fausto; LEIVA, Tomaz Puga; NUNES, Ivani Aparecida; ROLLO, Joao Manuel Domingos de Almeida
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
Until now the martensitic stainless steel type AISI-420 is widely used in the manufacture of surgical implements. These implements present premature corrosion problems identified after cleaning, sterilization and cutting edge loss and/or rupture during the surgical processes.. This study evaluates the steel as to the chemical composition, hardness, microstructure and pitting corrosion resistance in a solution of enzyme detergent diluted in water by anodic cyclic polarization. This mixture is used in the cleaning of surgical implements that are submerged in this solution for 2 h before cleaning and sterilization. The results show steels with martensite microstructures in the ferrite phase, together with impurities. These presented low pitting potential values in compariston to steels with a fully martensitic microstructure.

Analysis of two reinforced concrete pile caps with embedded sockets in the presence of a locking beam

BARROS, Rodrigo
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
The present research studies the behavior of reinforced concrete locking beams supported by two capped piles with the socket embedded; used as connections for pre-cast concrete structures. The effect provoked by locking the beam on the pile-caps when supported by the lateral socket walls was evaluated. Three-dimensional numerical analyses using software based on the finite element method (FEM) were developed considering the nonlinear physical behavior of the material. To evaluate the adopted software, a comparative analysis was made using the numerical and experimented results obtained from other software. In the pile caps studied, a variation in the wall thickness, socket interface, strut angle inclination and action on beam. The results show that the presence of a beam does not significantly change pile cap behavior and that the socket wall is able to effectively transfer the force from the beam to the pile caps. By the tensions on the bars of longitudinal reinforcement, it was possible to obtain the force on the tie and the strut angle inclination before the collapse of models. It was found that the angles present more inclinations than those used in the design, which was made based on a strut-and-tie model. More results are available at http://www.set.eesc.usp.br/pdf/download/2009ME_RodrigoBarros.pdf

Analytical solutions for geometrically nonlinear trusses; Soluções analíticas para treliças geometricamente não lineares

GRECO, Marcelo; VICENTE, Carlos Eduardo Rodrigues
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
408.48496%
This paper presents an analytical method for analyzing trusses with severe geometrically nonlinear behavior. The main objective is to find analytical solutions for trusses with different axial forces in the bars. The methodology is based on truss kinematics, elastic constitutive laws and equilibrium of nodal forces. The proposed formulation can be applied to hyper elastic materials, such as rubber and elastic foams. A Von Mises truss with two bars made by different materials is analyzed to show the accuracy of this methodology.; O artigo apresenta uma metodologia analítica para analisar treliças com severo comportamento não linear geométrico. O objetivo principal do trabalho é encontrar soluções analíticas para treliças com diferentes esforços axiais nos elementos estruturais. A metodologia é baseada na cinemática estrutural, nas leis constitutivas elásticas e no equilíbrio de forças nodais. A formulação proposta pode ser aplicada em materiais hiperelásticos, como borracha e espumas com comportamento elástico. Uma treliça do tipo Von Mises com duas barras feitas de materiais diferentes é apresentada como exemplo de aplicação, com o objetivo de demonstrar a precisão e eficiência do método proposto.

Chemical composition of mixed construction and demolition recycled aggregates from the State of Sao Paulo

Ulsen, Carina; Kahn, Henrique; Angulo, Sérgio Cirelli; John, Vanderley Moacyr
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
Construction and Demolition Waste (CDW) represents. about 50% of the total Brazilian municipal solid waste: thus, recycling represents huge benefits both in environmental and economic perspectives. Herein, the chemical characterization results of three samples from two different recycling plants from the State of Sao Paulo is prevented. The results demonstrated that the visual classification into grey and red is not related to the chemical composition but mostly to the grain size fraction. The chemical composition of the CDW varies according to the content of cement paste, natural aggregates (quartz sand or granite), red ceramic and clay. Furthermore, the production of recycled concrete aggregates requires two crushing stages to meet the technical standards. The sand fraction (below 4.8 mm) presents high grades of SiO(2), which indicates the liberation of cement paste to fines (< 0.15 mm). The fines have a great potential to be used in the cement industry.

Avaliação do desempenho ambiental de obras de recuperação de rodovias; Environmental performance evaluation in highway rehabilitation works

Costa, Roberta Maria; Sanchez, Luis Enrique
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
408.48496%
This paper features a tool to carry out environmental performance evaluation in highway rehabilitation works, as a component of environmental supervision activities. The procedure involves (i) evidence gathering by conducting technical inspections and reviewing environmental compliance reports, (ii) ranking nonconformities according to a proposed weighting framework, and (iii) calculation of an environmental conformity index. For the sake of testing and calibration, the procedure was applied to five road segments that were submitted to rehabilitation works in Sao Paulo State and the results were treated qualitatively.; Esse trabalho apresenta um instrumento de avaliação do desempenho ambiental para obras de recuperação de rodovias. Os resultados da avaliação podem ser divulgados às partes interessadas e usados pelas empresas e órgãos públicos responsáveis pelo gerenciamento rodoviário para, entre outros, atestar a conformidade ambiental da empresa construtora. O procedimento envolve (i) aquisição dos dados por meio de vistorias e análise de relatórios ambientais, parte das atividades de supervisão ambiental de obras rodoviárias, (ii) classificação de não conformidades ambientais segundo uma escala de importância...

Sphericity of apatite particles determined by gas permeability through packed beds

Pinto, Thiago César de Souza; Lima, Odair Alves de; Leal Filho, Laurindo de Salles
Fonte: SOC MINING METALLURGY EXPLORATION INC Publicador: SOC MINING METALLURGY EXPLORATION INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
514.6508%
Because shape is an assessment of the three-dimensional form of a particle, it may be described in terms of sphericity (Psi), which is a measure of how closely a particle approaches a spherical configuration. In this study, Darcy`s law and the Kozeny-Carman model for fluid flow through porous media were applied to packed beds to determine the sphericity (Psi) of apatite particles. The beds were composed of glass spheres or particles of apatite (igneous from Brazil and sedimentary from the United States) of three classes of size (Class 1: -297 +210 mu m; Class 2: -210 +149 mu m; Class 3: -149 +105 mu m). Glass spheres were used to validate the model because of its known sphericity (Psi = 1.00). Apatite particles, either igneous or sedimentary, showed very close values for particle sphericity (Psi approximate to 0.6). Observations on particle images conducted by scanning electron microscopy illustrated that igneous (Psi = 0.623) and sedimentary (Psi = 0.644) particles of apatite of Class 2 predominantly exhibit elongated shape. The close value of particle sphericity (Psi approximate to 0.6) showed by either igneous or sedimentary apatite may be justified by the similarity in particle shape.; CNPq; CAPES

Suspension of apatite particles in a self-aerated Denver laboratory flotation cell

Lima, Odair Alves de; Marques, Celio Vitor Pereira; Leal Filho, Laurindo de Salles
Fonte: SOC MINING METALLURGY EXPLORATION INC Publicador: SOC MINING METALLURGY EXPLORATION INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
514.6508%
Effective solids suspension is a necessary precondition for particle collection, and solids suspension is largely dependent on the hydrodynamics of the flotation cell. This study attempted to correlate the status of the suspension of apatite particles of different sizes in a Denver laboratory flotation cell versus the impeller rotational speed (N) adopted to operate the machine. The latter variable (N) influences the impeller capacity to lift the particles from the bottom of the tank and also to disperse them throughout the volume of the vessel. Such an impeller capacity can be characterized by the critical impeller speed for the accomplishment of solids off-bottom suspension (N(z)) and also by the velocity of the radial water flow discharged by the impeller (U) divided by the particle terminal settling velocity (U(s)). This way, the status of the suspension of apatite particles inside the flotation cell can be characterized by one of three categories: ""segregation"" (N/N(2) < 0.60 and U(s)/U > 0.08); ""suspension"" (0.60 <= N/N(2) < 1 and 0.06 < U(s)/U < 0.10); and ""dragging"" (N/N(2) >= 1 and U(s)/U <= 0.03). The range of impeller rotational speed (N), which was able to suspend the finest particles (D(p) = 90,mu m), was unable to suspend the coarsest particles (D(P) = 254 mu m). Conversely...

Surface tension of flotation solution and its influence on the selectivity of the separation between apatite and gangue minerals

Martins, Marisa; Leal Filho, Laurindo de Salles; Parekh, Bhupendra Kumar
Fonte: SOC MINING METALLURGY EXPLORATION INC Publicador: SOC MINING METALLURGY EXPLORATION INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
514.6508%
This work presents and discusses the influence of the surface tension (gamma(LV)) of methanol/water mixtures on the flotation response of apatite versus gangue minerals conditioned with flotation reagents (75 g/t cornstarch and 100 g/t Berol 867) at pH 10.6. Berol 867 is a collector composed of sodium alkyl sarcosinate plus nonionic surfactant. The highest Schulz efficiency of separation (recovery of apatite minus recovery of gangue) was achieved at approximate to 51.0 mN/m. The critical surface tension of wettability (gamma(C)) of apatite was found to occur at 34.7 mN/m when determined by means of gamma flotation experiments, , and it was 33.9 mN/m when determined by Zisman`s approach.; Fapesp (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[00/01949-4]; CAPES

Comparison between DC(+) and Square Wave AC SAW Current Outputs to Weld AISI 304 for Low-Temperature Applications

TOMA, R. E.; BRANDI, S. D.; SOUZA, A. C.; MORAIS, Z.
Fonte: AMER WELDING SOC Publicador: AMER WELDING SOC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
516.26496%
Welded equipment for cryogenic applications is utilized in chemical, petrochemical, and metallurgical industries. One material suitable for cryogenic application is austenitic stainless steel, which usually doesn`t present ductile/brittle transition temperature, except in the weld metal, where the presence of ferrite and micro inclusions can promote a brittle failure, either by ferrite cleavage or dimple nucleation and growth, respectively. A 25-mm- (1-in.-) thick AISI 304 stainless steel base metal was welded with the SAW process using a 308L solid wire and two kinds of fluxes and constant voltage power sources with two types of electrical outputs: direct current electrode positive and balanced square wave alternating current. The welded joints were analyzed by chemical composition, microstructure characterization, room temperature mechanical properties, and CVN impact test at -100 degrees C (-73 degrees F). Results showed that an increase of chromium and nickel content was observed in all weld beads compared to base metal. The chromium and nickel equivalents ratio for the weld beads were always higher for welding with square wave AC for the two types of fluxes than for direct current. The modification in the Cr(eq)/Ni(eq) ratio changes the delta ferrite morphology and...

Assessment of the cavitation erosion resistance in high nitrogen austenitic stainless steels: study of the wear mechanisms

Grajales, Dairo Hernan Mesa; Garzon, Carlos Mario; Tschiptschin, Andre Paulo
Fonte: ESCOLA DE MINAS Publicador: ESCOLA DE MINAS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
412.63445%
Specimens of a UNS S31803 steel were submitted to high temperature gas nitriding and then to vibratory pitting wear tests. Nitrided samples displayed fully austenitic microstructures and 0.9 wt. % nitrogen contents. Prior to pitting tests, sample texture was characterized by electron backscattering diffraction, EBSD. Later on, the samples were tested in a vibratory pit testing equipment using distilled water Pitting tests were periodically interrupted to evaluate mass loss and to characterize the surface wear by SEM observations. At earlier pit erosion, stages intense and highly heterogeneous plastic deformation inside individual grains was observed. Later on, after the incubation period, mass loss by debris detachment was observed. Initial debris micro fracturing was addressed to low cycle fatigue. Damage started at both sites, inside the grains and grain boundaries. The twin boundaries were the most prone to mass-loss incubation. Grains with (101) planes oriented near parallel to the sample surface displayed higher wear resistance than grains with other textures. This was attributed to lower resolved stresses for plastic deformation inside the grains with (101); surface texture.

Macrosegregation of Impurities in Directionally Solidified Silicon

MARTORANO, M. A.; FERREIRA NETO, J. B.; OLIVEIRA, T. S.; TSUBAKI, T. O.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
529.5511%
Directional solidification of molten metallurgical-grade Si was carried out in a vertical Bridgman furnace. The effects of changing the mold velocity from 5 to 110 mu m seconds(-1) on the macrosegregation of impurities during solidification were investigated. The macrostructures of the cylindrical Si ingots obtained in the experiments consist mostly of columnar grains parallel to the ingot axis. Because neither cells nor dendrites can be observed on ingot samples, the absence of precipitated particles and the fulfillment of the constitutional supercooling criterion suggest a planar solid-liquid interface for mold velocities a parts per thousand currency sign10 mu m seconds(-1). Concentration profiles of several impurities were measured along the ingots, showing that their bottom and middle are purer than the metallurgical Si from which they solidified. At the ingot top, however, impurities accumulated, indicating the typical normal macrosegregation. When the mold velocity decreases, the macrosegregation and ingot purity increase, changing abruptly for a velocity variation from 20 to 10 mu m seconds(-1). A mathematical model of solute transport during solidification shows that, for mold velocities a parts per thousand yen20 mu m seconds(-1)...

Investigation of the corrosion behaviour of AA 2024-T3 in low concentrated chloride media

QUEIROZ, F. M.; MAGNANI, M.; COSTA, I.; MELO, H. G. de
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
508.48496%
Aluminium alloy (AA) 2024-T3 is an important engineering material due to its widespread use in the aerospace industry. However, it is very prone to localized corrosion attack in chloride containing media, which has been mainly associated to the presence of coarse intermetallics (IMs) in its microstructure. In this work the corrosion behaviour of AA 2024-T3 in low concentrated chloride media was investigated using microscopy and electrochemical methods. TEM/EDS observations on non-corroded samples evidenced the heterogeneous composition within the IMs. In addition, SEM observations showed that intermetallics with the same nominal composition present different reactivity, and that both types of coarse IMs normally found in the alloy microstructure are prone to corrosion. Moreover, EDS analyses showed important compositional changes in corroded IMs, evidencing a selective dissolution of their more active constituents, and the onset of an intense oxygen peak, irrespective to the IM nature, indicating the formation of corrosion products. On the other hand, the results of the electrochemical investigations, in accordance with the SEM/EDS observations, evidenced that IMs corrosion dominates the electrochemical response of the alloy during the first hours of immersion in the test electrolyte. (c) 2008 Elsevier Ltd. All rights reserved.; FAPESP (Sao Paulo); CAPES; CNPq (Brazilian)

Bronze metallurgy in Iron Age central Europe : a metallurgical study of Early Iron Age bronzes from Stična, Slovenia.; Metallurgical study of Early Iron Age bronzes from Stična, Slovenia

Cooney, Elizabeth Myers
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 2 v. (381 leaves)
ENG
Relevância na Pesquisa
541.6224%
The Early Iron Age (750-450 BCE) marks a time in the European Alpine Region in which cultural ideologies surrounding bronze objects and bronze production were changing. Iron was becoming the preferred material from which to make many utilitarian objects such as weapons and agricultural tools; this change can be clearly seen in the different treatments of bronze object deposits from the Late Bronze Age to the Early Iron Age. The Early Iron Age hillfort settlement of Sticna in what is now southeastern Slovenia was one of the first incipient commercial centers to take advantage of the new importance placed on iron, conducting trade with Italy, Greece, the Balkans, and northern Europe. This metallurgical study of bronze funerary objects from Sticna identifies construction techniques, use patterns, and bronze metallurgical technologies from the ancient region of Lower Carniola. This information is then used to explore the cultural importance of bronze at Early Iron Age Sticna and to compare the bronze work of Lower Carniola with that of other regions in central Europe and Italy from this time of great change in Iron Age Europe.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.; This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.; Includes bibliographical references (v. 2...

Using the ultrasound and instrumented indentation techniques to measure the elastic modulus of engineering materials

MEZA, J. M.; FRANCO, E. E.; FARIAS, M. C. M.; Buiochi, Flávio; Souza, Roberto Martins de; CRUZ, J.
Fonte: CENIM Publicador: CENIM
Tipo: Artigo de Revista Científica
SPA
Relevância na Pesquisa
508.48496%
Currently, the acoustic and nanoindentation techniques are two of the most used techniques for material elastic modulus measurement. In this article fundamental principles and limitations of both techniques are shown and discussed. Last advances in nanoindentation technique are also reviewed. An experimental study in ceramic, metallic, composite and single crystals was also done. Results shown that ultrasonic technique is capable to provide results in agreement with those reported in literature. However, ultrasonic technique does not allow measuring the elastic modulus of some small samples and single crystals. On the other hand, the nanoindentation technique estimates the elastic modulus values in reasonable agreement with those measured by acoustic methods, particularly in amorphous materials, while in some policristaline materials some deviation from expected values was obtained.