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COB112 ANÁLISE DE IMAGENS TOMOGRÁFICAS DE MATERIAIS COMPÓSITOS E METÁLICOS / ANALYSIS OF TOMOGRAPHIC IMAGES OF COMPOSITE AND METALLIC MATERIALS

Célio Maschio & Antonio Celso Fonseca de Arruda

Faculdade de Engenharia Mecânica, Universidade Estadual de Campinas - UNICAMP - CEP 13.083-970, Caixa Postal 6122 - Campinas, São Paulo, Brasil - E-mail: celio@columbia.dep.fem.unicamp.br ou celio@dep.fem.unicamp.br; celso@dep.fem.unicamp.br

X-ray computed tomography (XCT), originally developed for medical purposes is becoming increasingly applied to several applications where it is necessary the interpretation of the internal structure of an object nondestructively. Due its qualitative and quantitative nature, XCT technique established to be a promising tool of nondestructive materials evaluation, and digital image processing emphasizes its applicability. A problem related to this technique are the artifacts, presents in high density material image, mainly metallic materials. One of most common artifacts are caused by beam hardening effect. This phenomenon occurs because the photons at lower energies are preferentially attenuated. Then, the effective energy of the beam shifts upwards as the beam travels through the medium. This work describes the use of digital filtering technique in metallic material images (basically aluminum), for beam hardening correction. Low-pass filter (frequency domain) and median filter (spatial domain) have been used. The results are demonstrated through graphical analysis of the images and measuring area of known defects, like holes in aluminum sample.

Keywords: Tomografia Computadorizada de Raios-X, Processamento Digital de Imagens, Ensaios Não Destrutivos / X-ray Computed Tomography, Digital Image Processing, Nondestructive Materials Evaluation

COB117 CHARACTERISATION OF CARBON/CARBON COMPOSITE MATERIALS FOR BRAKE DISCS

Flaminio Levy Neto, Alexandre C. de Freitas & Carlos A. A. Cairo

Departamento de Engenharia Mecânica, Faculdade de Tecnologia - UnB - FT - ENM

CEP 70.910-900 Brasilia, DF, Brasil - E-mail: levy@orion.enm.unb.br

The purpose of this work was to measure the hardness, the density, the interlaminar shear and bending strengths, as well as the flexural modulus of Carbon/Carbon (C/C) specimens extracted from the brake disks of a supersonic aircraft and a F1 racing car. Two kinds of hardness tests were adopted: ( i ) Rockwell L and ( ii ) Micro Vickers. For the flexural modulus the methods of sonic resonance ( non destructive) and three point bending (destructive) were used. The interlaminar shear and the bending strengths were obtained by three point bending only. The repeatability of the results for the aircraft brakes (solid disk) was in the range of 3% to 22%. For the F1 brakes, in which the disks had ventilation holes (i.e. cylindrical ducts distributed along the radial direction), the variations were in the range of 13% to 25%.

Keywords: Composite brakes, Mechanical Properties, Carbon / Carbon Composites.

COB118 DESIGN OF A TEST FIXTURE TO EVALUATE THE TRANSVERSE SHEAR STRENGTH OF COMPOSITE MATERIALS

Flaminio Levy Neto & Willian Mota Baldoino

Departamento de Engenharia Mecânica, Faculdade de Tecnologia - UnB - FT - ENM

CEP 70.910-900 Brasilia, DF, Brasil - E-mail: levy@orion.enm.unb.br

This experimental investigation is concerned with the design, manufacture, and operation of a test fixture to evaluate the transverse shear strength of unidirectional composite rods. Fifteen specimens of carbon/carbon (c/c) composite were tested to failure, using an Instron machine to apply a compressive load on the new apparatus. The results are presented and analyzed in the paper.

Keywords: Carbon/carbon composites, Transverse Shear Strength.

COB363 MOLDAGEM POR INJEÇÃO APLICADA À RECICLAGEM DE PET DE GARRAFAS DE REFRIGERANTES / INJECTION MOLDING APPLIED TO POST-CONSUMER PET RECYCLING

Sandro Donnini Mancini, Maxwell Nascimento Bezerra & Maria Zanin

Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rodovia Washington Luís, Km 235, CEP: 13565-905, Tel: (016) 274-8250, e-mail:psdm@iris.ufscar.br

Post-consumer PET soft-drink bottles, after size reduction, washing and drying were submitted to multiple injection processing. Tensile, impact and differential scanning calorimetry (DSC) were made in samples of this recycled PET. The results of tensile and impact properties are related to cristalinity (which increased when the followed recyclings are made) and processing, after comparation with the results of the same tests in samples made by extrusion.

Keywords: Injeção, PET, Extrusão, Reciclagem / Injection, PET, Extrusion, Recycling

COB384 DESENVOLVIMENTO DE UM PROCESSO PARA FABRICAÇÃO DE PEÇAS EM MATERIAL COMPOSTO PARA APLICAÇÕES AUTOMOBILÍSTICAS / DEVELOPMENT OF A MANUFACTURING PROCESS TO PARTS IN COMPOSITE MATERIAL FOR AUTOMOTIVE APPLICATIONS

Araujo, Geraldo Accetturi de

Departamento de Engenharia Mecânica - EPUSP - Cidade Universitária - São Paulo - SP

Mercedes-Benz do Brasil S.A. - GPP, E-mail: gaaraujo@usp.br

Ferreira, Marcelo Prior & Merlotte, Claudemir & Ueda, Marcos Cesar Sussumu Ueda & Xavier, Marcelo

Mercedes-Benz do Brasil S.A. - GPP, Av. Alfred Jurzykowski, 562 - Vila Paulicéia - CEP 09880-900 - São Bernardo do Campo/SP

E-mail: ppl01@ mercedes-benz.com.br

This work presents the development of a new composite part production process for the automotive industry and describes its impact on the current industry demands, such as: market globalization, shorter project and production times, lower production costs, higher production variability (smaller batches, according to customer demands) and the need for a faster product line exchange with higher quality levels. Facing this new reality, the T.R.V. (Vacuum Resin Transfer) process, a new technology which concerns resin impregnation under vacuum, will be stated as a composite part production process. The T.R.V. process is patent pending at INPI - The Brazilian Institute for Industrial Property - and is the result of the engineers and technicians experiences, who used scientific principles for this development at an important automotive industry in Brazil.

Keywords: Composites, automotive manufacturing process, materiais compostos, processos de fabricação

COB546 OPTIMIZATION OF FILAMENT WOUND PARTS USING NON-GEODESIC WINDING

Jonas de Carvalho, Mieke Lossie^* & Dirk Vandepitte^*

Departamento de Engenharia Mecânica, Escola de Engenharia de São Carlos - USP, CEP 13560-250 São Carlos,SP, Brasil - E-mail: prjonas@sc.usp.br

^* Katholieke Universiteit Leuven, Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, PMA, Celestijnenlaan 300B, B-3001 Heverlee, Belgium - E-mail: lossie@ mech.kuleuven.ac.be

The basis of the filament winding process is the high-speed precise lay-down of continuous reinforcements in prescribed patterns. The possibility to orient the fibres in the most appropriate directions makes filament winding a very attractive process for the manufacturing of high performance components. However, the fibre paths cannot be freely chosen; in order to obtain an accurate fibre placement, the fibres may not slip on the surface during winding. Thus, the selection of slip-free paths in such a way to obtain a part with optimal strength and minimum weight, is the most important step in the design of filament wound parts. This paper describes two design optimization methodologies based on non-geodesic winding. A first methodology concerns the optimization of individual paths and a second methodology concerns the coverage optimization of "tube-like" parts. Both methodologies have been implemented in a computer integrated environment. Experimental validations are included and the results discussed.

Keywords: Composites, Design, Filament winding, Optimization, Non-geodesics Compósitos, Projeto, Otimização, Enrolamento filamentar, Não-geodésicas.

COB561 AVALIAÇÃO DA ESTABILIDADE TÉRMICA DE PC, PBT E DA BLENDA PC/PBT PARA FINS DE RECICLAGEM / THERMAL STABILITY EVALUATION OF PC, PBT AND PC/PBT BLEND FOR RECYCLING PORPOSE.

Elisabete Maria Saraiva Sanchez*, Joceli Maria Giacomini Angelini*, Caio Glauco Sanchez** & Fernando Luis Pacheco De Resende**

*CPqD - TELEBRÁS - CEP 13083-970 - Caixa Postal 6088 - Campinas - Brasil - e-mail: sanchez@cpqd.br

**DETF - FEM - UNICAMP - CEP 13081-970 - Caixa Postal 6122 - Campinas - Brasil - e-mail: caio@fem.unicamp.br

The aim of this paper is to show the studies that have been made with engineering thermoplastics and blends in order to see the thermal stability to commercial recycling process. These is important today because there is a increasing in the application of different concentration of reutilized material by the processing industry; so, the evaluation of the degradation degree and how this affect the end product’s properties must be made. For this purpose, the following materials and techniques were utilized: polycarbonate (PC), polybutylene terephthalate (PBT) and it’s blend (PC/PBT); melt flow index, dilute solution viscosity, and thermogravimetric analysis.

Keywords: Reciclagem, termoplástico, degradação térmica, índice de fluidez, estabilidade térmica, termogravimetria.

Recycling, thermoplastics, thermal degradation, melt flow index, thermal stability, thermogravimetric analysis.

COB564 ESTUDO DO EFEITO DO "SIZE" EM FIBRAS DE CARBONO UTILIZANDO A TEORIA DE WEIBULL / THE STUDY OF SIZE EFFECT OF CARBON FIBERS BASED ON WEIBULL THEORY

Ana Léa Dotan*, Giovanni Ciliato, e Hazim Ali al-Qreshi*

Departamento de Tecnologia, Divisão de Mecânica-Aeronáutica - ITA - CTA - S. J. dos Campos, e-mail: lea@mec.ita.cta.br

The mechanical properties of T300 carbon fibers (with and without sizing) have been measured at lengths of 1,0, 2,5, 5,0 and 10,0 cm, and the usefulness of the Weibull treatment in correlating the results tested. Other failure modes for carbon fibers have also been observed, based on Weibull distribution, such as the "clamp effect" on expected tensile strength of fibers at small gauge lengths.

Keywords: Fibras de carbono, tensão de ruptura, módulo de elasticidade, distribuição de Weibull, efeito garra, size, carbon fibers, tensile strength, young modulus, Weibull distribution, clamp effect.

COB567 RESISTÊNCIA AO CISALHAMENTO DE UNIÕES AÇO ZINCADO / EPÓXI / AÇO FOSFATIZADO / SHEAR STRENGTH OF ZINCATED STEEL / EPOXY ADHESIVE / PHOSPHATIZED STEEL JOINTS

Astrid Damasco¹, Itamar Ferreira², Marcelo C. Gandur³, Pedro A. P. Nascente¹ e Nelson G. Alcântara¹

1 Centro de Caracterização e Desenvolvimento de Materiais, Departamento de Engenharia de Materiais, Universidade Federal de

São Carlos, CEP 13565-905 São Carlos, SP, Brasil. ccdm@power.ufscar.br.

2 Departamento de Materiais, Faculdade de Engenharia Mecânica, Universidade Estadual de Campinas, CEP 13083-970

Campinas, SP, Brasil.

3 Divisão de Adesivos e Químicos, 3M do Brasil Ltda, Caixa Postal 123, CEP 13001-970 Sumaré, SP, Brasil.

The effects of sheet thickness (1.5 and 2.0 mm), cleaning state of the surface of the steel sheets (in a condition without cleaning and by using Metal Ethyl Ketone as a cleaner), and test time after bonding (24 and 96 hours) on the shear strength of galvanized steel / epoxy adhesive / phosphatized steel joints hava been analyzed. The results showed that the sheet thickness and the cleaning state of the steel sheets had no effect the shear strength; for these conditions the shear strength was about 9.7 MPa. On the other hand, the test time after bonding had a significant effect on the shear strength; the shear strength for the 24 h test time after bonding was 9.4 MPa and 10.4 MPa for 96 h. In all cases the standard deviation was very low: maximum of 5%.

Keywords: Metal/adhesive joints, Shear strength, Steel, Epoxy.

COB571 SIMULAÇÃO DO PERFIL DE TEMPERATURA NO DISPOSITIVO DE ALTA PRESSÃO PARA SÍNTESE DE MATERIAIS SUPERDUROS / SIMULATION OF TEMPERATURA PROFILE IN HIGH PRESSURE DIVECE OF SUPERHARD MATERIAL SYNTHESIS

João José de Assis Rangel, Serguei Mourachov & Vladimir Poliakov

Universidade Estadual do Norte Fluminense - UENF - CCT - LAMAV

CEP 28015-620 Av. Alberto Lamego, 2000, Campos dos Goitacazes, RJ, Brasil - E-mail: jjrangel@uenf.br

A computational model to analyse the synthesis process of carbonado type synthetic polycrystalline diamond was performed through numerical simulation. In this model it is possible to analyse temperature distribution in a part of chamber in both steady and nonsteady states. The simulation results allowed an understanding of the influence of temperature profile in chamber as well as the effect of increasing voltage in the temperature distribution during the synthesis process.

Keywords: Diamante policristalino, carbonado, distribuição de temperatura, simulação de perfil, análise numérica.

Polycrystalline diamond, carbonado, temperature distribution, profile simulation, numerical analysis.

COB978 SINTERIZAÇÃO DE COMPÓSITOS Fe-NbC COM ADITIVOS DO SISTEMA Fe-Cu-P: ESTUDOS DILATOMÉTRICO E MICROESTRUTURAL / MICROSTRUCTURAL AND DILATOMETRIC CHARACTERIZATION OF Fe-NbC COMPOSITES SINTERED WITH Fe-Cu-P ADDITIVES

Jorge Hebert Echude-Silva, Vilson João Batista, Antonio Eduardo Martinelli & Aloisio Nelmo Klein

Departamento de Engenharia Mecânica, LABMAT - UFSC - Florianópolis

Caixa Postal 5192, CEP 88.040-970 Florianópolis, SC, Brasil - E-mail: jhebert@matrix.com.br

NbC was added to iron to investigate an alternative approach for the production of hard phase composites by mechanical alloying. The powders were mixed in toluene using an attrition mill during 8 h. The slurry was then dried out and the powder was mixed to 0.8 wt.% graphite and 4 wt.% Cu3P-Fe as the sintering additive. Two different compositions were investigated, corresponding to eutectic points of the ternary Cu-Fe-P phase diagram. Next, the samples were uniaxially pressed and sintered in a H2 atmosphere. Different sintering profiles were followed based on data gathered by differential thermal analysis. This work shows the dilatometric behavior of the sintered materials and the microstructural analysis carried out by scanning electron microscopy and energy dispersive spectroscopy. The results confirmed the potential of the Cu3P-Fe as a sintering additive. Nevertheless, further experiments are required to achieve similar levels of densification to those obtained with the Fe3P additive.

Keywords: Sinterização, Compósitos, Moagem, Sintering, Composites, Attritor

COB1037 INFLUÊNCIA DE ALGUNS PARÂMETROS DO PROCESSO DE MOLDAGEM A VÁCUO NA QUALIDADE DAS PEÇAS ACABADAS / INFLUENCE OF SOME PARAMETERS OF THE VACUUM MOULDING PROCESS IN THE QUALITY OF THE FINAL COMPONENT

Raimundo Nonato Barbosa Felipe¹, Renata Carla Tavares dos Santos Felipe¹ & Eve Maria Freire de Aquino²

1.Escola Técnica Federal do Rio grande do Norte - CEMEC - ETFRN

2.Programa de Pós-Graduação em Engenharia Mecânica - Centro de Tecnologia - UFRN

CEP 59072-970 Campus Universitário S/N - Natal - RN - Brasil, E - mail: eve@ct.ufrn.br

The vacuum moulding process manufacturing process of strengthened plastic containing fiber glass, requires the control of some parameters, so that a good surface finishing and improved mechanical properties of the final component can be achieved. Among the important parameters one can highlight: the vacuum pressure, resin’s viscosity and density. The aim of this work is to establish how strong these parameters affect the component final quality. The analysis was based on a large range consisting of several values for pressure, viscosity and density. The type of resin used for the process was unsaturated polyester (ALPOLIT LP 8242) and the reinforcements were based on choppy roving blanket type (300g/m²). Both visual inspection and microscopy were used to analyze the final components. The calcination process was used in order to quantify the resin’s volume, the fiber’s volume and the hollow spaces inside the material. The viscosity was measured by a BROOKFIEL viscometer type where both the viscosity and density were altered due to the addition of a maximum of 10% of estyrene considering the final volume. The analysis confirmed viscosity, density and pressure have a direct effect on both the process and the achieved component’s surface finishing.

Keywords: materiais compostos, fibra de vidro/poliéster, processo de moldagem a vácuo, parâmetros de controle / composite materials, fiber glass/polyest, vacuum moulging process, control of parameters

COB1035 ESTUDO DO COMPORTAMENTO MECÂNICO E FRATURA DE RESERVATÓRIOS OBTIDOS PELO PROCESSO DE MOLDAGEM A VÁCUO / STUDY OF THE MECHANICAL BEHAVIOR AND FRACTURE OF RESEVOIRS MOLDED BY VACUUM MOULDING PROCESS

Renata Carla Tavares dos Santos Felipe¹, Raimundo Nonato Barbosa Felipe¹& Eve Maria Freire de Aquino²

1.Escola Técnica Federal do Rio grande do Norte - CEMEC - ETFRN

2.Programa de Pós-Graduação em Engenharia Mecânica - Centro de Tecnologia - UFRN

CEP 59072-970 Campus Universitário S/N - Natal - RN - Brasil, E - mail: eve@ct.ufrn.br

This work is the result of an experimental investigation about the damage mechanism on both unsaturated polyester plastic (ALPOLIT LP 8242) and fiber glass made reservoirs. The reservoirs were obtained through the vacuum moulding process and the reinforcements were based on choppy roving blanket type (300g/m²). The material is submitted to both tensile and three-point bending efforts under two conditions: dry and wet. The two techniques used to analyze the mechanical fracture were optics microscopy and micrography. For both test conditions, it is highlighted the die cracking, the non-adhesive behavior between the die and the fiber and the breakage of the fibers.

Keywords: materiais compostos, fibra de vidro/poliéster, propriedades mecânicas, característica do dano / composite materials, fiber glass/polyester, mechanical properties, absorption moisture, characteristic damage

COB1067 BENEFICIAMENTO DO QUARTZO NATURAL BRUTO: CONSTRUÇÃO DE INSPECTOSCÓPIO E ORIASCÓPIO/PROCESSING OF RAW NATURAL QUARTZ: CONSTRUCTION OF INSPECTOSCOPY AND ORIASCOPY

Henara L. Costa, Rafael A. Gonçalves & José Daniel B. de Mello

Laboratório de Tribologia e Materiais, Departamento de Ciências Físicas - UFU

38400 901 - Uberlândia - MG - E-mail: ltm-henara@ufu.br

Raw natural quartz is mainly used by electronic industries in resonators and pre-defined frequency generation high precision devices. Quartz crystals with adequate quality and size are significantly found only in Brazil, including Minas Gerais state. The present paper aimed the implementation of a laboratorial infrastructure to aid the qualification of natural quartz. In a first phase, an equipment that determines the optical axis of the crystals in order to allow its posterior precise orientation with X-ray techniques was constructed. This equipment, named inspectoscopy, aid also the inspection of raw crystals about macro-defects as color, cracks, twins and inclusions. In a second step, an oriascopy was constructed. This equipment allow the initial determination of X and Y axis and the detection of electrical twins in conveniently etched quartz plates. The oriascopy also allows to determine if the crystal is right-handed or left-handed. The development of this phase was associated to sulfuric acid etching techniques. The precision cutting of the plates used a diamond-wheel cutting machining. Both inspectoscopy and oriascopy are operational and the obtained results are satisfactory.

Keywords: Quartz, inspectoscopy, defects, chemical etching, cutting.