Análise microestrutural e propriedades mecânicas do aço DP 600

Seeking to meet the requirements: relatively low cost of materials and wide applicability in the automotive industry. The best option was the steel Dual Phase (DP), because that is lighter, have high formability, meet the cost requirements and applicability, steel Dual Phase (DP) came to meet these requirements with its two-phase microstructure, ferrite and martensite microstructure who claim to respect and mechanical properties. In this context, the aim of this study was to correlate the microstructure revealed in metallography to the mechanical properties observed in hardness and tensile tests. The microstructure is revealed by etching in 2% nital and then captured images of the sample were processed in ImageJ software to aid in determining the volume fraction of the phases present. Therefore, the mechanical properties were evaluated with respect to volume fraction of the steel layers and analyzed DP 600 together with the mechanical properties obtained by Rockwell hardness test and tensile test. With the values of the mechanical properties calculated and tested, it was possible to describe the method of metallography, as the attack phase and counts, so that it can use this relationship tested/calculated property as a qualitative analytical tool. The method used for the correlation between the microstructure and mechanical properties confirmed the importance of the phases present in the Dual Phase steel to obtain the desired mechanical properties in the application of the steel

Efeito do tratamento alcalino da fibra na resistência mecânica do compósito epóxi/capim-sapê

Due to growing concerns for reducing environmental damage caused by the use of non-renewable raw materials, there is a growing demand for research related to aggregate technology with environmental preservation. Thus, the use of non-renewable materials and less aggressive materials has been gaining attention. About composite materials, the exchange of synthetic fibers by natural fibers, especially vegetable fiber as reinforcement, has been increasing, due to its physical-chemical properties such as mechanical strength, nontoxic, low cost, low density, processing flexibility, non-abrasive to the process equipment, requiring simple surface treatments, etc. This objective was to process composites reinforced with long fibers of sapegrass in epoxy matrix and characterize the composites through mechanical tests. Three groups of composites were prepared according to the treatment received by the reinforcement: without treatment, alkali treatment at concentration of 5% w/v and alkali treatment at 10% w/v concentration. The materials were analyzed by tensile and flexural, and tests also optical microscopy and scanning electron microscopy (SEM). The results were statistically analyzed. As the main result, the alkali treatment of 5% in the sapegrass fibers increases the tensile and flexural strength, as a consequence of the improve adhesion between matrix and reinforcement

Análise microestrutural de tubos API N80 soldados pelo processo HF/ERW para prospecção de petróleo e gás

On the grounds of the great advances achieved over recent years, the process HF/ERW (High-Frequency/Electric Resistance Welding)welded pipe have played an active role in the oil and gas industry for deep water applications, at high and extremely low temperatures, under high pressure and in highly corrosive environments, gradually replacing manufactured pipes by other processes. However, studies have shown that defects in the welded joints are a the leading causes of pipelines failures, which has required the determination of toughness values in this region, in compliance with the strict recommendations of the codes and standards with manufacturers and construction companies, on the oil and gas sector. As part of the validation process required toughness values, this research project focuses on a microstructural analysis in HF / ERW tubes microalloyed, steel grade API 5CT N80, designed to explore oil and gas in deep waters, the subject of strategic relevance to the country because of the recent discoveries in the Santos mega fields: Tupi and Libra (pre-salt). In this scientific work will be presented and discussed the results of mechanical tensile and Charpy, a few CTOD tests curves (showing the trend of toughness values to be obtained), and the microstructures of the base material obtained by optical microscopy, with special emphasis on the formation of non-metallic inclusions in the welded joint

Comportamentos, térmico e mecânico, de compósitos de polipropileno e resíduo da hidrólise enzimática do bagaço de cana de açúcar

Pós-graduação em Engenharia Mecânica - FEG

Confecção e avaliação de chapas de madeira aglomerada com aproveitamento de resíduos de marcenaria industrial

Pós-graduação em Engenharia Civil - FEIS

Estudo da influência da adição de resíduos de óleo em concretos para aplicação em pavimentos

Pós-graduação em Engenharia Civil - FEIS

Avaliação da pressão liquórica em pacientes obstétricas submetidas à anestesia subaracnoidea que apresentaram cefaleia pós-punção dural

Pós-graduação em Anestesiologia - FMB

Fadiga em compósitos 5HS carbono/epóxi processados via RTM: relação entre cargas axiais no plano e modos de delaminação

Pós-graduação em Engenharia Mecânica - FEG

Cimentação de coroas com fosfato de zinco sobre munhões de liga de titânio, irradiados ou não por laser

By means of tensile strength, NiCr total crowns were removed from machine-made conical abutments composed by an Ti-6Al-4V alloy. In a total of 20 abutments, 10 were used with it surface presenting high smoothness and 10 abutments had its surfaces modifi ed by laser both cemented with zinc phosphate. The mechanical test was performed at a MTS 810 universal machine adjusted to a speed of 0.5 mm/m. The statistical analysis was done by Levene’s test, which showed homogeneity of variances among groups (F =2.21; p < 0.1). “Student t test” showed that signifi cant differences were found between groups. The modifi cation of the abutment surface through laser caused an increase in pull-out resistance of crowns cemented with zinc phosphate from 430.66 N to 1.514,87 N.

Desempenho de trator agrícola em operação de preparo do solo utilizando diesel e proporções de biodiesel de babaçu

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Propriedades antimicrobianas, físico-mecânicas e de liberação de fluoreto do cimento de ionômero de vidro associado ao hexametafosfato de sódio microparticulado e nanoparticulado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Concreto com adição de cinza de bagaço de cana-de-açúcar

Pós-graduação em Engenharia Civil - FEIS

Efeito do tipo de adesivo e do seu mecanismo de ativação, assim como da viscosidade da resina composta, na resistência de união à dentina antes e após envelhecimento artificial

Pós-graduação em Odontologia Restauradora - ICT

Influência de três tratamentos de superfície para cerâmicas a base de zircônia na resistência adesiva e no comportamento à fadiga do material

Pós-graduação em Odontologia Restauradora - ICT

Painéis de Medium Density Fiberboard fabricados com bagaço de cana-de-açúcar e madeira de reflorestamento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)