Efeito do Estrôncio (Sr) no tratamento de modificação do eutético da liga Al-1%Si

This study aimed to analyze the cooling curves, micro and macrograph alloy Al-1 %Si without the addition of strontium modifier and with the addition of the same. One of the ways of improving mechanical properties of alloy Al -Si is through the modification process. For the experiments two billets of the alloy Al-1%Si cast iron mold in a billet with addition of 0.02% strontium by weight, and the other billet without the addition of modifier were fused. In the solidification process of billet temperature was monitored and recorded every second for later plotting in Origin 8 program and analyzes the cooling curves obtained. The billets were cut and passed by grinding and polishing to perform the macrograph and micrographs. The results concerning the macrograph indicated that billet without the addition of Strontium particle size obtained was more refined than the billet where the strontium modifier was added. Regarding the micrograph, photos stemmed from the optical microscope didn´t show the expected modification effect by the addition of Strontium. This suggests that the low amount of silicon (1 %) present in the alloy used in this study interfered in the change process, because according to the literature review, Strontium 0.022 % by weight is sufficient to fully modify an alloy with 7% Silicon. The results from the cooling curve showed that both the eutectic temperature and the solidification time remained unchanged with the addition of strontium

Analise comparativa do desempenho de ferramentas no torneamento do aluminio 2024

The aluminium alloys are used in many fields because of their versatility combined with the excellent aluminium’s properties, mentioned in the study. This study aims to compare the performance of polished Hard Metal, Hard Metal covered with TiB2 and High Speed Steel (HSS) tools, at the aluminium 2024 alloy’s turning, as a function of variation of some turning parameters such as: feed, depth of cut and cutting speed; and study the surface finish and the required power during turning by processing the output data, like analyze the chip’s features for each used tool. The results provide information of the tool’s material effects, when submitted to different turning conditions, about the output variable in question. In this way, it was possible to notice that although the Hard Metal covered with TiB2 tool has provided the better surface finish, the chip’s features were better when the turning was accomplished by the Polished Hard Metal tool. In relation to the required turning’s power, the lowest consumption occurred with the High Speed Steel tool

Caracterização mecânica e microestrutural de juntas de alumínio 6013 T4 soldados a laser

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do tratamento térmico nas propriedades mecânicas e resistência ao desgaste de um ferro fundido branco multicomponente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de tubo ARBL contendo 1Cr 0,2Mo fabricado pelo processo ERW/HF destinado à indústria de petróleo e gás

Pós-graduação em Engenharia Mecânica - FEG

Efeito dos oxi-ânions do grupo VIB sobre a corrosão aquosa das ligas Al(2024) e Al(7050) utilizadas na indústria aeronaútica

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

Efeito de oxigênio na biocompatibilidade e propriedades da liga Ti-15Mo

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Avaliação de ciclo de vida comparativa dos processos de anodização e oxidação eletrolítica com plasma de liga de alumínio

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Influência da temperatura e do pH do meio sobre a resistência à corrosão das ligas Al(20204-T3), Al(7010-T7) e Al(7050-T7) utilizadas na indústria aeronáutica

Pós-graduação em Engenharia Mecânica - FEG

Estudo da fragilização ao revenido em aço liga de 2,25CR-1MO através do ensaio de indentificação instrumentada

2,25Cr-1Mo alloy steels are widely used in petrochemical plant equipments working in high temperature conditions because of their good mechanical proprieties in these conditions. Although, when exposed for a long time at high temperature, in the rage of 343 °C to 593 °C, may present the temper embrittlement phenomenon. The component named stripper of assembly converter of fluid catalytic cracking unit (UFCC) of studied plant is manufactured using this material, which is subject to temper embrittlement. The phenomenon of temper embrittlement refers to progressive lose of toughness, making the material brittle. With embrittlement, equipaments manufactured with this material are under risks to suffer brittle fracture in the cool down and start-up situations of them, which can cause catastrophic failures. By this reason, this research studies presence of temper ebrittlement phenomenon on this material. To verify the toughness of the material is conventionally used charpy V-notch test. However, this test requires the removing of samples of the material to make specimens. This fact becomes critical when talk about structural components of an equipment. So, this research also studies a non-destructive test that can be executes in-situ, known as instrumented indentation, as an alternative detection of the phenomenon at the component stripper, by comparative of the mechanical proprieties obtained by conventional tests in similar samples

Estudo da usinagem por torneamento de ligas de alumínio

The non-ferrous materials have got so many mechanical, physical and chemical advantageous properties so that is provided to them consolidated position in industry. In this context, aluminium alloys have been seen a lot on many applications of engineering areas – specially on automotive, aeronautical and aerospace due to their main properties such as low density, high corrosion resistance, favorable structure weight / material resistance relation, among others characteristics that are mencioned through this study. This study aims to analyze the aluminium alloys behavior on a general context when they are used on turning process, taking for examples the 6262 and 7050 aluminium alloys. In this way, the analysis studies the datas obtained during the turning tests realized on 3 steps each one; those datas are concerning the medium and total rugosities – obtained with the assistance of a portable Surface Roughness Finish Tester, as well as the chips obtained during the tests - visual analysis, and the cutting tools wear – with the assistance of an optical microscope, under different conditions of application of cutting fluids (dry machining, application of coolant in abundance and MQL – Minimum Quantity of Lubricant). The results concerning this study show detailed information about influence of cutting fluids on the machining by turning of the aluminium alloys related on this work and also about aluminium alloys in general when they are used on turning processes with different conditions from one another. By this way, it was evident the MQL technique is the best one for the 6262 alloy. However, for 7050 alloy, it was evident that the dry machining is responsible for the best results

Metodologia de determinação das curvas de probabilidade de falha S-N-P para uma liga de aluminio submetida a diferentes tratamentos termicos de solubilização e precipitação

The approach of the subject matter in this work relies on the fact that the reliability of methods for performance analysis of materials proves critical for the result. This work focused on the development and presentation of the methodology for lifting probability curves for fatigue test (SN) according to standard E739, this focus is justified by the fact that the results in fatigue test show considerable dispersion making it difficult to reading and interpretation of data, this dispersion arises because the phenomenon of rupture is strongly influenced by internal characteristics of the material, we can then have much data ranging from test to test. Thus we set out originally for a brief study of aluminum alloys in question, as well as the treatments to which they were subjected. We also studied the behavior of materials when subjected to cyclic loading, which configures process of fatigue failure, and even fatigue test method in question. This statistical analysis is based on the ASTM E739 standard, so its contents was studied in detail so that we could present in detail the methodology and raise SN curves for different aluminum alloy 7012 subjected to fatigue test. Data were collected from tests conducted in the department of materials from two samples of aluminum alloy 7012 solubilized and precipitated by different time intervals and assayed temperature fatigue-type traction-compression, these data were then analyzed and used to survey curves using the base as E739. After lifting the curve analyzed the characteristics of the test samples and their correlation with the test results. We confirmed the effectiveness of the method of statistical analysis by ASME E739, which allowed the reading of data without this method would be very difficult to have a reading and comparison of the results for the two types... (Complete abstract click electronic access below)

Avaliação da usinagem do INCONEL 718

The nickel superalloys are known as being a material with poor machinability, they have some properties like high hardness, good resistance at high temperature, tendency to weld with the tool material at high temperature, etc. In the aerospace, biomedical and petrochemical industry, are increasing the need to use materials that resist to aggressive process and environment. In these uses, it has increased the use of nickel-based superalloys like Inconel 718 and consequently the need to research new techniques and tools to improve the machinability of this material. For the superalloys and resistant alloys at high temperatures is considered that the difficulty in the machining regards to the combination of the relatively high cutting forces and high temperatures that grow during the machine process, causing deformation or breakage of the cutting tool. This work purpose is to develop the study of the machining of external cylindrical turning of the nickel based alloy Inconel 718, using ceramic tools, seeking the optimization of machining this alloy, looking to provide real productive increases without the need of investments in new production means. The machining test were accomplished using commercials hard metal tools and the results were compared each other to find the best tool and the best parameter. The conclusion is that the tool TNMG160408-23 -class 1005- was the better one, when used with the parameter 60_15_08

Caracterização da liga do sistema binário Ti-15Mo para aplicações biomedicas

As they have excellent mechanical properties, corrosion resistance and biocompatibility, much research has been conducted with respect to biomedical applications of titanium alloys. This work aims to study the experimental system binary alloy Ti-15Mo, in the raw state of fusion and heat treatment after homogenization, solubilization and calcination (simulating conditions employed for nanotube growth) targeting biomedical applications. Samples were obtained by casting the components in an electric arc furnace with inert atmosphere of argon. After obtaining the alloy, it was heat treated at three different heat treatments, namely homogenizing, calcining and simulation solubilization. The phases present were analyzed by X-ray diffraction, optical microscopy and microhardness testing

Estudo das alterações das propriedades mecânicas em aço A-516 grau 70 soldado e submetido a tratamento térmico de alívio de tensões

Pressure vessels are equipments that require a great care because of their high cost and human life risk in case of fail, and its fabrication methods are different for each manufacturer. Normally, pressure vessels and its parts are fabricated by welding, which may change local properties of metals. The head of a pressure vessel is a very important structural component and it is fabricated by welding and mechanical conformation. Because its excellent mechanical properties, de steel A-516 Grade 70 is often used in manufacturing of large pressure vessels that are subjected to high pressure and temperature, but was verified that its mechanical resistance is decreased when submitted to a tension relief heat treatment. By experience it was defined that before mechanical conformation of the head of a large pressure vessel, the steel should be submitted to a stress relief heat treatment in order to facilitate the mechanical conformation, but there is no quantitative analysis to prove this method and study its possible risks. In the present work the steel A-516 Grade 70 demonstrated a decrease of its mechanical resistance when submitted to a stress relief heat treatment, but keeping above the minimum limit defined in the literature. By other side its ductility was substantially increased, being possible to deduce that the stress relief heat treatment before mechanical conformation is a viable e recommended technique, but with reservations. With the data acquired during the fabrication e preparation of the specimen and the result of the tests, it was possible to elaborate a welding procedure that provides the same results obtained in this present work