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Caracterização de material composto de matriz metálica a partir de um liga de alumínio aeronáutico; Characterization of metal matrix composite material from an aeronautical aluminum recycled alloy

Kavalco, Patrícia Mariane
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 06/10/2011 PT
Relevância na Pesquisa
521.05367%
Materiais compostos de matriz metálica (CMM) vêm sendo estudados para diversas aplicações. Entretanto, pouco estudo é apresentado na sua confecção a partir de materiais reciclados. Este trabalho teve como objetivo a caracterização de um material composto de matriz metálica (CMM), utilizando material reciclado como matéria prima. Foram usados aparas de chapas de liga de alumínio 2024 descartados para a matriz e carbeto de silício (SiC) como reforço, sendo a produção realizada através do processo de fabricação com base na técnica de conformação por spray para possível aplicação em componentes automotivos. Foi realizado o tratamento térmico do material e a caracterização, determinando as propriedades de dureza, resistência mecânica, resistência ao desgaste, MEV e EDS. Foram ensaiadas amostras do material composto fundido e extrudado, bem como de ferro fundido de uma peça automotiva e da liga de alumínio 2024. Observou-se que o CMM ainda precisa de melhorias no processo de produção para obter propriedades de dureza e resistência que permitam que ele possa ser usado como um substituto para o ferro fundido, porém o mesmo apresentou melhores propriedades quando comparado com o material da matriz.; Metal matrix composites (MMC) have been studied for several applications. However...

Corrosion and tribocorrosion behaviour of Al-Si-Cu-Mg alloy and its composites reinforced with B4C particles in 0.05M NaCl solution

Toptan, F.; Alves, A. C.; Kerti, I.; Ariza, E.; Rocha, L. A.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 27-35
ENG
Relevância na Pesquisa
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The corrosion behaviour of metal matrix composites (MMCs) is strictly linked with the presence of heterogeneities such as reinforcement phase, microcrevices, porosity, secondary phase precipitates, and interaction products. Most of the literature related to corrosion behaviour of aluminium matrix composites (AMCs) is focused on SiC reinforced AMCs. On the other hand, there is very limited information available in the literature related to the tribocorrosion behaviour of AMCs. Therefore, the present work aims to investigate corrosion and tribocorrosion behaviour of Al-Si-Cu-Mg alloy matrix composites reinforced with B4C particulates. Corrosion behaviour of 15 and 19% (vol) B4C reinforced Al-Si-Cu-Mg matrix composites and the base alloy was investigated in 0.05M NaCl solution by performing immersion tests and potentiodynamic polarisation tests. Tribocorrosion behaviour of Al-Si-Cu-Mg alloy and its composites were also investigated in 0.05M NaCl solution. The tests were carried out against alumina ball using a reciprocating ball-on-plate tribometer. Electrochemical measurements were performed before, during, and after the sliding tests together with the recording of the tangential force. Results suggest that particle addition did not affect significantly the tendency of corrosion of Al-Si-Cu-Mg alloy without mechanical interactions. During the tribocorrosion tests...

Estudo do processo de fabricação de compósitos AA6061 + TiCN por sinterização com fase líquida e caracterização do produto; Investigation on the process of production of composites AA6061 + TiCN by powder metallurgy involving liquid phase sintering and characterization of the product

Jaime Alejandro Bravo Salazar
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/02/2007 PT
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620.7635%
Este trabalho estuda o processo de fabricação de compósitos de matriz de alumínio AA6061 reforçado com TiCN por metalurgia do pó, envolvendo as etapas de mistura de pós, compactação uniaxial e sinterização com fase líquida. Para efeitos de comparação foram produzidos e caracterizados compactados da liga AA6061 sem adição de reforços. Foram investigados os parâmetros de processo: teores de reforço (5% e 10% massa), teor de aditivos Pb e Sn (0,1, 0,15, 0,2 e 0,4% massa), pressão de compactação (400, 600 e 800 MPa), tempos (15, 30, 45 e 60 min) e temperatura de sinterização (590, 600, 610 e 620 ºC). Em cada etapa do processo foram caracterizados os produtos (mistura de pós e compactados); o produto final obtido, após sinterização, foi caracterizado com relação à sua microestrutura, propriedades físicas (densificação e variação dimensional) e mecânicas (resistência à flexão e dureza). Os resultados obtidos mostraram uma grande eficiência do processo na obtenção de compósitos; a adição do teor de reforço de 5%TiCN foi eficiente na promoção de rupturas das camadas de óxidos do pó da liga de alumínio compactado à pressão de 400 MPa, auxiliando a sinterização por difusão da fase líquida formada a partir da fusão de Al+Mg2Si...

Efeito de tratamentos térmicos nas propriedades em compressão de compósitos de baixa densidade de matriz metálica; Heat treatment effect in the properties in compression of low density metal-matrix composites

Everton Marques Nascimento
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 29/08/2014 PT
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Este trabalho analisa a influência de tratamentos de solubilização e envelhecimento na estrutura e propriedades de compósitos de baixa densidade de matriz da liga AA7075 reforçada com partículas cerâmicas porosas de cinasita (SiO2/Al2O3/Fe2O3) ou vermiculita (SiO2/Al2O3/MgO), produzidos por tixoconformação. Foram empregadas as condições de tratamento: solubilização a 470ºC por 12 horas e envelhecimento a 170ºC por 24 horas. Os materiais produzidos foram caracterizados nas condições tixoconformada, solubilizada e envelhecida. Nos compósitos no estado tixoconformado foram analisadas a densidade e a usinabilidade em processo de corte por jato de água abrasivo (AWJM), para determinação do Número de Usinabildade (N) de cada tipo de compósito. Os compósitos foram também analisados quanto à sua microestrutura (por MO e MEV), a distribuição dos principais elementos de liga (Zn, Mg e Cu) na matriz metálica, a microdureza da matriz metálica, o comportamento mecânico sob compressão semi-estática e compressão dinâmica (impacto) nas três condições citadas. Resultados mostraram que os compósitos produzidos apresentam, no estado tixoconformado, densidades relativas da ordem de 0,5 e número de usinabilidade por jato abrasivo (N) cerca de 20% superior ao da liga sem reforço. Quanto ao efeito do tratamento térmico na microestrutura dos compósitos...

Wear mechanisms in functionally graded aluminium matrix composites : effect of the lubrification by an aqueous solution

Gomes, J. R.; Ribeiro, A. R.; Vieira, A. C.; Miranda, A. S.; Rocha, L. A.
Fonte: Trans Tech Publications Publicador: Trans Tech Publications
Tipo: Artigo de Revista Científica
Publicado em //2005 ENG
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824.072%
Abstract. Functionally graded aluminium matrix composites reinforced with SiC particles are attractive materials for a broad range of engineering applications in the automotive, aircraft, sports, military and aerospace industries, whenever a superior combination of surface and bulk mechanical properties are required. In general, these materials are developed for the production of high wear resistant components. Also, often this kind of mechanical part operates in the presence of aggressive environments, such as marine atmospheres. In this work, aluminium composites with functionally graded properties, obtained by centrifugal cast, are characterised by reciprocating pin-on-plate sliding wear tests against nodular cast iron. Three different volume fractions of SiC reinforcing particles in each functionally graded material were considered. Sliding experiments were performed with and without the presence of a lubricant (3% NaCl aqueous solution). All tests were carried out at room temperature, under a normal load of 10N and constant frequency (1 Hz) and stroke (6 mm). In the case of the lubricated tests, electrochemical parameters (corrosion potential) were monitored during sliding. The worn surfaces as well as the wear debris were characterised by SEM/EDS. Friction values were in the order of 0.42 for unlubricated conditions...

The effect of reinforcement volume ratio on porosity and thermal conductivity in Al-Mgo composites

Calin,Recep; Pul,Muharrem; Pehlivanli,Zühtü Onur
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 EN
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In this study, the effects of reinforcement volume ratios (RVR) on composite structure and thermal conductivity were examined in Al-MgO reinforced metal matrix composites (MMCs) of 5%, 10% and 15% RVR produced by melt stirring. In the production of composites, EN AW 1050A aluminum alloy was used as the matrix material and MgO powders with particle size of -105 µm were used as the reinforcement material. For every composite specimen was produced at 500 rev/min stirring speed, at 750 °C liquid matrix temperature and 4 minutes stirring time. Composite samples were cooled under normal atmosphere. Then, microstructures of the samples were determined and evaluated by using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) analysis. In general, it was observed that the reinforcement exhibited a homogeneous distribution. Furthermore, it was determined that the increase in the RVR increased porosity. From the Scanning Electron Microscope images, a thermal Ansys model was generated to determine effective thermal conductivity. Effective thermal conductivity of Al-MgO composites increased with the decrease in reinforcement volume ratio.

Centrifugal infiltration of particulate metal matrix composites : process development and fundamental studies/

Wannasin, Jessada, 1977-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 125 p.; 5599402 bytes; 5597118 bytes; application/pdf; application/pdf
ENG
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513.67383%
A high-pressure liquid infiltration process utilizing centrifugal force was designed and laboratory equipment developed. In this process, a mold containing reinforcing materials was located at the end of an elongated runner, which was filled with a molten metal. Rotation of the runner created centrifugal force driving infiltration. To obtain high pressures, the metal head was controlled to be long and constant throughout the process. Threshold pressures required for infiltration of several packed ceramic powders were determined using the laboratory equipment built. Achievable pressures were up to 150 atm for Sn-15 wt% Pb. The pressures allowed SiC, TiC, and A1203 powders ranging in sizes from 25 [mu]m to 300 [mu]m, packed to a high volume fraction, to be infiltrated by Sn-15 wt% Pb. Threshold pressure results obtained agree well with experimental results previously reported, and with calculated values. Observations of the resulting composite structures showed layering and porosity defects. Layering defects, but no porosity defects, were observed in the composite samples containing coarse powders. In contrast, the composites containing fine powders possess porosity defects, but not layering defects. The layering defect was attributed to the depacking mechanism of the powders during the cold pressing process. The porosity defect was attributed to insufficient applied pressures. A new packing process was proposed to avoid layering in coarse powders. Macrosegregation and microsegregation were limited in all samples. The interparticle spacings of these composites were smaller than the dendrite arm spacing would have been at equivalent cooling rates; thus...

Plasma And Cold Sprayed Aluminum Carbon Nanotube Composites: Quantification Of Nanotube Distribution And Multi-Scale Mechanical Properties

Bakshi, Srinivasa R
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
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Carbon nanotubes (CNT) could serve as potential reinforcement for metal matrix composites for improved mechanical properties. However dispersion of carbon nanotubes (CNT) in the matrix has been a longstanding problem, since they tend to form clusters to minimize their surface area. The aim of this study was to use plasma and cold spraying techniques to synthesize CNT reinforced aluminum composite with improved dispersion and to quantify the degree of CNT dispersion as it influences the mechanical properties. Novel method of spray drying was used to disperse CNTs in Al-12 wt.% Si pre-alloyed powder, which was used as feedstock for plasma and cold spraying. A new method for quantification of CNT distribution was developed. Two parameters for CNT dispersion quantification, namely Dispersion parameter (DP) and Clustering Parameter (CP) have been proposed based on the image analysis and distance between the centers of CNTs. Nanomechanical properties were correlated with the dispersion of CNTs in the microstructure. Coating microstructure evolution has been discussed in terms of splat formation, deformation and damage of CNTs and CNT/matrix interface. Effect of Si and CNT content on the reaction at CNT/matrix interface was thermodynamically and kinetically studied. A pseudo phase diagram was computed which predicts the interfacial carbide for reaction between CNT and Al-Si alloy at processing temperature. Kinetic aspects showed that Al4C3 forms with Al-12 wt.% Si alloy while SiC forms with Al-23wt.% Si alloy. Mechanical properties at nano...

High temperature dry sliding friction and wear behavior of aluminum matrix composites (Al₃Zr+α-Al₂O₃)/Al; High temperature dry sliding friction and wear behavior of aluminum matrix composites (Al(3)Zr+alpha-Al(2)O(3))/Al

Zhu, H.; Jar, C.; Song, J.; Zhao, J.; Li, J.; Xie, Z.
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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Heguo Zhu, Cuicui Jar, Jinzhu Song, Jun Zhao, Jianliang Li, Zonghan Xie

Microstructure and high temperature wear of the aluminum matrix composites fabricated by reaction from Al-ZrO₂-B elemental powders; Microstructure and high temperature wear of the aluminum matrix composites fabricated by reaction from Al-ZrO(2)-B elemental powders

Zhu, H.; Jia, C.; Li, J.; Zhao, J.; Song, J.; Yao, Y.; Xie, Z.
Fonte: Elsevier Science Sa Publicador: Elsevier Science Sa
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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625.44957%
Heguo Zhu, Cuicui Jia, Jianliang Li, Jun Zhao, Jinzhu Song, Yinqun Yao, Zonghan Xie

Microwave combustion synthesis of in situ Al₂O₃ and Al₃Zr reinforced aluminum matrix composites; Microwave combustion synthesis of in situ Al(2)O(3) and Al(3)Zr reinforced aluminum matrix composites

Zhu, H.; Hua, B.; Cui, T.; Huang, J.; Li, J.; Xie, Z.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
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Abstract not available; Heguo Zhu, Bo Hua, Tao Cui, Jiewen Huang, Jianliang Li, Zonghan Xie

Effect of alumina particle additions on the aging kinetics of 2014-aluminum matrix composites

Harper, Christopher Paul.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
638.72434%
Differential Scanning Calorimetry (DSC) was conducted on 2014 aluminum, 2014 aluminum reinforced with 10 and 15 percent by volume of alumina particles, 2024 aluminum, and a A1/4%Cu alloy. Electrical resistivity and matrix micro-hardness measurements were conducted on the 2014 aluminum alloy and the metal matrix composites (MMC) during isothermal aging. Transmission Electron Microscopy (TEM) and DSC were used to identify the metastable phases formed in the 2014 aluminum alloy. The effect of alumina particle addition on the precipitation, growth and thermal stability of the metastability phases in the 2014 aluminum alloy and MMC were studied. Results were used to characterize the effect of the alumina reinforcement on the aging kinetics of the 2014 aluminum alloy matrix

Effect of alumina particle additions of the aging kinetics of 6061 aluminum matrix composites

Allen, Susan Marie.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
609.4497%
Approved for public release, distribution is unlimited; Differential scanning calorimetry (DSC) was conducted using a monolithic 6061 aluminum material and two 6061 aluminum matrix composite materials. The composite materials were reinforced with 10 volume percent and 15 volume percent alumina particles. Electrical resistivity and hardness measurements during isothermal aging treatments were also conducted. The effects of prior aging and alumina particle additions on the growth kinetics and the thermal stability of the metastable phases in each material were studied. The results were used to characterize the effect of reinforcement on the aging kinetics of composite materials.

Anodization mechanism on SiC nanoparticle reinforced al matrix composites produced by power metallurgy

Ferreira, Sonia C.; Conde, Ana; Arenas, Maria A.; Rocha, Luis A.; Velhinho, Alexandre
Fonte: Mdpi Ag Publicador: Mdpi Ag
Tipo: Artigo de Revista Científica Formato: 8151-8167
ENG
Relevância na Pesquisa
735.705%
Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiCnp. The current peaks and the steady-state current density recorded at each voltage step increases with the SiCnp volume fraction due to the oxidation of the SiCnp. The formation mechanism of the anodic film on Al/SiCnp composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiCnp in the anodic film.

Synthesis, Characterization and Dry Sliding Wear Behavior of In-situ Formed TiAl3 Precipitate Reinforced A356 Alloy Produced by Mechanical Alloying Method

Dursun,Özyürek; Tansel,Tuncay; Hatice,Evlen; İbrahim,Çiftci
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 EN
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In this present study, the effect of in-situ formed TiAl3 and AlTiSi intermetallic phases within A356 aluminum alloy on the dry sliding wear behaviors was investigated. The TiAl3 and AlTiSi intermetallic phases were obtained by synthesizing A356 aluminum alloy containing 6% titanium for different times (1, 4, 8 and 16h). The cold pressed samples were sintered in an argon atmosphere at 530 °C for one hour (10 °C/min.) and then cooled in the furnace. The sintered samples were synthesized at 550 °C for different times (1, 4, 8 and 16h), and the in-situ aluminum matrix composites (AMCs) were produced. Wear tests of the AMCs were performed under 30 N load and at 1 ms-1sliding speed for five different sliding distances. As the result of the studies performed, formation of in-situ TiAl3 and AlTiSi intermetallic phases were detected. With the increase in synthesizing time, the porosity in the structure was found to be reduced. In addition, it was observed that the densities and hardness of the composites increased depending on the synthesizing time. The wear test results revealed that increasing hardness values of A356 + 6% Ti AMCs decreased the weight loss.

WC-Co Particles Reinforced Aluminum Matrix by Conventional and Microwave Sintering

Ghasali,Ehsan; Pakseresht,Amir Hossein; Agheli,Maryam; Marzbanpour,Amir Hossein; Ebadzadeh,Touradj
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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Metal matrix composites of Al-WC (10, 15 and 20 wt%) were prepared by microwave (without holding) and conventional sintering (held for 1 hour) processes at various temperatures between 650-950 °C. The results indicated that the highest density of conventional and microwave sintering corresponds to 97.4 ± 1.2% and 98.6 ± 0.8 of theoretical density, respectively; The highest bending strength of conventional and microwave sintered samples were 223 ± 12 and 256 ± 12 MPa, respectively. XRD patterns showed the decomposition of WC particles and formation of Al5W and Al12W interfacial reaction product phases in both processes. SEM studies showed that WC reinforcement particles were more likely to be agglomerated in microwave compared to conventional sintering process.

Production of MA956 Alloy Reinforced Aluminum Matrix Composites by Mechanical Alloying

Gomes,Luiz Antonio Carlos Moutinho; Travessa,Dilermando Nagle; González-Carrasco,Jose Luis; Lieblich,Marcela; Cardoso,Katia Regina
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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940.7802%
Aluminum matrix composites (AMC) are attractive structural materials for automotive and aerospace applications. Lightweight, environmental resistance, high specific strength and stiffness, and good wear resistance are promising characteristics that encourage research and development activities in AMC in order to extend their applications. Powder metallurgy techniques like mechanical alloying (MA) are an alternative way to design metal matrix composites, as they are able to achieve a homogeneous distribution of well dispersed particles inside the metal matrix. In this work, aluminum has been reinforced with particles of MA956, which is an oxide dispersion strengthened (ODS) iron base alloy (Fe-Cr-Al) of high Young’s modulus and that incorporates a small volume fraction of nanometric yttria particles introduced by mechanical alloying. The aim of this work is to investigate the use of MA to produce AMC reinforced with 5 and 10 vol.% of MA956 alloy particles. Homogeneous composite powders were obtained after 20 h of milling. The evolution of morphology and particle size of composite powders was the typical observed in MA. The composite powders produced with 10 vol.% MA956 presented a more accentuated decrease in particle size during the milling...

Mathematical model predicts the elastic behavior of composite materials

Boari,Zoroastro de Miranda; Monteiro,Waldemar Alfredo; Miranda,Carlos Alexandre de Jesus
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2005 EN
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Several studies have found that the non-uniform distribution of reinforcing elements in a composite material can markedly influence its characteristics of elastic and plastic deformation and that a composite's overall response is influenced by the physical and geometrical properties of its reinforcing phases. The finite element method, Eshelby's method and dislocation mechanisms are usually employed in formulating a composite's constitutive response. This paper discusses a composite material containing SiC particles in an aluminum matrix. The purpose of this study was to find the correlation between a composite material's particle distribution and its resistance, and to come up with a mathematical model to predict the material's elastic behavior. The proposed formulation was applied to establish the thermal stress field in the aluminum-SiC composite resulting from its fabrication process, whereby the mixture is prepared at 600 °C and the composite material is used at room temperature. The analytical results, which are presented as stress probabilities, were obtained from the mathematical model proposed herein. These results were compared with the numerical ones obtained by the FEM method. A comparison of the results of the two methods...

Exploring diffusion of ultrasonically consolidated aluminum and copper films through scanning and transmission electron microscopy

Sietins, Jennifer
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
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513.3181%
Gillespie, John W.; Advani, Suresh G.; Ultrasonic consolidation (UC) is a promising manufacturing method for metal matrix composite pre-preg tapes or foils that utilizes a layer build-up technique. The process involves three main variables: applied load, oscillation amplitude, and rolling speed. A main advantage of this process is the ability to manufacture multi-material parts at lower processing temperatures compared to other metal matrix composites processes. A major disadvantage, however, is a lack of understanding of diffusion during the ultrasonic consolidation process, which is expected to affect the microstructure, bond quality, and strength within the interface region. The role of diffusion during the low temperature, short duration ultrasonic consolidation process was explored. First, scanning electron microscopy (SEM) x-ray energy dispersive spectroscopy (XEDS) was used to measure concentration profiles of ultrasonically consolidated high purity aluminum and copper through which the interdiffusion coefficients were calculated. It was found that the experimental accelerating voltage had a significant impact on the measurement of the concentration profiles, and associated interdiffusion coefficients, due to the interaction volume interference. The effect of the interaction volume on the concentration profiles was confirmed through Monte Carlo simulations of electron trajectories...

Comparative Study of Corrosion Behavior of AA2014/15 Vol%Al2o3p and AA2009/20 Vol% SiCw

Jamaludin,S.B.; Yusoff,Z.; Ahmad,K.R.
Fonte: Sociedade Portuguesa de Electroquímica Publicador: Sociedade Portuguesa de Electroquímica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
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509.50508%
The influence of heat treatment on the corrosion behavior of two aluminium matrix composites (AA2014/15 vol% Al2O3p - composite A and AA2009/20 vol% SiCw -composite B) was analyzed in 3.5% sodium chloride solution. The kinetic of the corrosion process was studied based on the gravimetric measurements. The corrosion damage and pit shape were analyzed by Image Analyzer. The corrosion damage in both composites was caused by the pitting attack on the surface. Pit shape of the composite A is different to the composite B. The corrosion rate of composite A is higher than composite B because the voids or gap between reinforcement particles and matrix are larger than in the composite B. The main attack of nucleation sites was at the interface region of the matrix and the reinforcement.