Estudo da fadiga em liga de alumínio aeronáutico 7475-T761

This work will address the study of fatigue conditions with constant load in an alloy of aluminum analysis 7475 - T761, so we can better understand the conditions of the aircrafts which contain this alloy in their structures. A literature review, which was discussed the concepts of fracture mechanics, fatigue, aeronautical components, chemical analysis of aluminum alloys, fatigue problems that appears in the aircrafts, metallographic analysis, and testing of optical microscopy tensile, fatigue and microhardness, surface analysis (MEV) study of the chemical composition of the alloy in question, the main causes of crashes, was performed, completing the work, analysis of data from tensile test, hardness and fatigue together with the interpretation of images of optical microscopy and scanning electron was taken. The data indicated the high mechanical strength of the alloy, along with its microstructure indicating elongated grains and high surface contour, which shows such resistance by hindering the movement of dislocations. The grooves are clearly shown in the MEV images as well as the classic with increased fatigue loading and subsequent reduction of the number of cycles to rupture behavior shown in the graphs. Therefore we observed the optimal behavior is supported by the league when subjected to fatigue loadings

Análise comparativa dos métodos MQL, MQL/Água e convencional na retificação cilíndrica do aço ABNT 52100, com rebolo de óxido de alumínio

Pós-graduação em Engenharia Mecânica - FEB

Contribuição ao estudo do desgaste de bedames na usinagem de ligas de alumínio-silício

Pós-graduação em Engenharia Mecânica - FEIS

Influência do desbalanceamento da onda retangular na liga de alumínio 6063-T6 soldada pelo processo TIG-CA

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Preparação e caracterização de óxido de alumínio anodizado sobre substratos transparentes

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Utilização de lama vermelha para oxidação eletrolítica assistida por plasma de liga de alumínio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do pré-mix de breu esterificado e policloreto de alumínio como agente de colagem interna em sistemas alcalinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação de desgaste para dois tipos diferentes de diamantes sintéticos CVD em sua utilização para a dressagem de ponta única de rebolos de óxido de alumínio

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo do efeito do transporte de massa nas curvas de polarização potenciodinâmica em ligas de alumínio da série 7XXX de aplicação aeronáutica

Aluminum Alloys are widely used as structural materials in the aerospace industry due to low weight, high mechanical strength and enduring corrosion resistance. Their resistance to corrosion is attributed to the rapidly formed stable oxide film (Al2O3) which spontaneously forms itself on the surface of the material. However, in the presence of aggressive ions, such as halide, Aluminum Alloys are subject to a localized process of corrosion. The electrochemical behavior of 7081-T73511 and 7050-T7451 Aluminum Alloys employed in the aerospace industry was investigated using a 0.6 M NaCl solution under the conditions of a controlled mass transport employing a rotating disk electrode. The theoretical limiting current density was determined by the Kouteki-Levich equation. The results confirmed that the inter-metallic Al7Cu2Fe acts as preferential cathode generating the galvanic coupling and the dissolution of the Aluminummatrix around it.

Influência de tratamentos a plasma na resistência à corrosão e na propriedade de adesão de uma camada protetiva sobre a superfície de ligas de alumínio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese e caracterização de alvo de óxido de zinco dopado com alumínio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da ativação da superfície de alumínio por íons de mercúrio e formação do amálgama Hg-Al: identificação do produto e cinética de reação

The activation of aluminum surface has the most various purposes as for example the search for the surface activation mechanism and the corrosion products by mercury ions. The objective of this work is to study the reactivity of the surface of aluminum metal when activated by mercury ions (Hg2+), with the consequent formation of an Al-Hg amalgam. Results demonstrate that the kinetics of the reaction, by measuring the mass change with time of the corrosion product formed between Al and Hg, and analysis by infrared spectroscopy (IR) that the product of the reaction between the amalgam, located on the surface, and the atmospheric oxygen is Al2O3 (aluminum hydroxide). The results also indicate that the kinetics of the reaction between the amalgam (Hg-Al) and atmospheric oxygen is of first order and reach a region where there is no more formation of product

Índice de clorofila em plantas de arroz de terras altas submetidas a estresse por alumínio e aplicação de silício

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aplicação de projeto de experimento no processo de manufatura de uma bobina de alumínio

TProducts must follow specifications in order to attend demands requested. In terms of rolled aluminum, one of the most significant items for customers is coil thickness. This is because only a tiny variation in thickness might cause a serious problem on customer's manufacturing line. Thereby, this research aims to analyze through design of experiments which factors and how they affect the thickness of aluminum coils. The response variable of the experiment is the thickness of aluminum coil, tensile strenght and yield strenght are the factors of the experiment and trimmers machines were considered as blocking. Data were obtained through tensile tests. The result of the experiment states that, according to the analysis of variance (ANOVA), while there is significant difference between the two levels of tensile strength, there is not any difference between the two levels of yield strength and trimmers machines. The thickness of the aluminum coils with high values of tensile strength tends to be thicker when compared with low values of tensile strength

Impactos causados por vibrações mecânicas em chapas de alumínio no processo de laminação a frio

This paper purpose is to analyze one of the main problems faced by cold rolling industry of the current time, the mechanical vibration. Factors such as strips with high velocity in order to increase the productivity and thickness becoming thinner and thinner cause the vibrations to be present at all times during rolling. These market requirements also drive the industry for technology development and thus bring the challenges that the operation of a new modern equipment and more powerful. The initial purpose is to analyze the forces that cause vibration in a rolling mill type four high with two stands, where is desirable to identify the origins of these vibrational forces to make possible dismiss them or at least control its intensity, in order to prevent damage in the rolling mill and ensure product quality to the customer. For it, will be used instruments to record and store the vibrations that occur during the lamination process. With this data will be able to analyze the characteristics of the vibrations and act at your elimination. At the end of the work is expected to demonstrate how important the critical view of the engineer in the analysis of graphics combined with the calculations of the natural vibration frequency and engagement of key parts of the laminator. With these two tools at hand, will be possible to increase the productivity of the rolling mill and act preventively in maintenance, thereby reducing your downtime and increasing its performance and efficiency