Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

Effect of titanium and nitrogen inoculation on the microstructure, mechanical properties and abrasive wear resistance of Hadfield Steels

Abstract The effect of titanium and nitrogen addition on Hadfield steels was investigated. In order to do this, two grades of steels were produced in terms of titanium and nitrogen addition. The final samples had their microstructure characterized and their mechanical properties ...

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Numerical Simulation of Hot Closed Die Forging of a Low Carbon Steel Coupled with Microstructure Evolution

Hot closed die forging is a regular process applied to manufacture metallic components used in supporting and fixing cable conductors in electric power transmission lines. In this forming process, the final microstructure of the workpiece depends on the control of several process...

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Effects of Macrosegregation and Microstructure on the Corrosion Resistance and Hardness of a Directionally Solidified Zn-5.0wt.%Mg Alloy

This study aims to analyze the influence of macrosegregation on microstructure evolution, and of microstructure length scale on the corrosion resistance of a Zn-5.0wt.%Mg alloy casting. The analyzed samples were taken along the length of castings unidirectionally solidified in un...

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Caracterização e análise macro e microestrutural de concretos fabricados com cimentos contendo escórias de alto-forno

The worldwide concern with the sustainable development has placed restrictions on the use of raw materials and on gas emissions in the atmosphere. In this scenario, the Brazilian cement industry has made significant changes in Portland cement compositions. These changes include t...

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Tri-modal Microstructure in Different Loading Zones Under TA15 Ti-alloy Isothermal Local Conventional Forging and Given Subsequent Heat Treatment

For TA15 Ti-alloy large-scale component, isothermal local conventional forging (ILCF) combined with subsequent heat treatment provides a feasible approach to obtain a tri-modal microstructure with attractive comprehensive performance. However the tri-modal microstructure characte...

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Effect of Track Overlap on the Microstructure and Properties of the CoCrMoSi PTA Coatings

Broadly speaking, the research and design of coatings are generally studied by way of single-track deposits; otherwise, the development of a coated part entails the understanding of how multi-track welding influences the microstructure and properties of the surface. This study ev...

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Effects of addition of iron (Fe) filings to green moulding sand on the microstructure of grey cast iron

Cast irons are important engineering materials, which possess a wide range of attractive properties. Their properties are significantly dependent on the microstructure of the cast, cast iron components. A way of controlling the microstructure of cast iron is through the control o...

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Investigation of sintered cobalt-zinc ferrite synthesized by coprecipitation at different temperatures: a relation between microstructure and hysteresis curves

The magnetic properties of sintered samples of cobalt-zinc ferrites produced from the corresponding coprecipitate were calculated based on hysteresis curves (Hc). The Hc values confirmed that soft ferrites were obtained by the procedure. A possible relation between the magnetic h...

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Effect of processing on microstructure and properties of CoCrMoSi alloy

CoCrMoSi alloys microstructure is affected by processing and their properties have been associated with the high volume fraction of Laves phase. However, not much has been reported on the effect of structure refinement and morphology on the properties of these alloys. This paper ...

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Study of Pipeline Steels with Acicular Ferrite Microstructure and Ferrite-bainite Dual-phase Microstructure

Three kinds of X70 steels with the same chemical composition and different microstructures fabricated by varying processes were compared in aspect of the microstructures and mechanical properties using SEM, TEM and tensile testing machine. The experimental results showed that the...

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Effect of Austenitizing Temperature on Mechanical Properties of the Mixed Bainite - Martensite Microstructure in CrMoV Steel

The effect of austenitizing temperature on mechanical properties of the mixed bainite - martensite microstructure in CrMoV steel was studied in the present work. The result showed that at low austenitizing temperature (910°C - 1000°C), the mixed microstructures containing 12-28% ...

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Three-dimensional characterization of pores in Ti-6Al-4V alloy

The direct three-dimensional characterization of opaque materials through serial sectioning makes possible to visualize and better quantify a material microstructure, using classical metallographic techniques coupled with computer-aided reconstruction. Titanium alloys are used as...

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Semisolid microstructure evolution of AZ91D magnesium alloy refined by Al-Ti-B

The microstructural evolution and corresponding phase transformations have been investigated during partial remelting of AZ91D magnesium alloy refined by Al-Ti-B master alloy. The effect of heating temperature on semisolid microstructure has also been discussed. The results indic...

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Avaliação da tenacidade à fratura de soldas de alta resistência e baixa liga pelo método da integral-J. / Evaluation of high strength low alloy steel weld metal fracture toughness using the J-integral method.

The influence of the microstructure on the fracture toughness behaviour of two groups of multipass High Strength Low Alloy (HSLA) steel weld metals, presenting different microstructure composition, was evaluated. The weld metals A1/A2 exhibited a microstructure composed by acicul...

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Influence of Microstructure on the Corrosion Resistance of AISI 317L (UNS S31703)

The AISI 317L stainless steel is an austenitic grade with at least 3%Mo. Recently, this steel has replaced AISI 316L in many applications in chemical and petrochemical industries, due to its higher pitting corrosion resistance. The microstructure of the hot rolled and annealed ma...

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Microestrutura e propriedades de porcelanas = Porcelain microstructure and technical properties / Porcelain microstructure and technical properties

A microestrutura de uma porcelana tradicional, queimada a diferentes temperaturas, foi analisada e relacionada com suas propriedades técnicas. Investigou-se por ceramografia a morfologia de fases, determinando-se a presença de quartzo, mulita primária e mulita secundária. Este es...

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The Influence of Microstructure and Mechanical Resistance on the Shape Memory of Ecae Processed Stainless Fe-Mn-Si-Cr-Ni-Co Steel

In the current work, XRD, SEM, EBSD and TEM techniques were used to evaluate the microstructure of stainless Fe-Mn-Si-Cr-Ni-Co shape memory steel processed by ECAE and annealed for one hour at temperatures ranging from 650ºC to 950ºC. The results were then correlated with the mec...

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Efeito do tratamento térmico do titânio sobre a proliferação de células pré-osteoblásticas

Titanium is a biomaterial widely employed in biomedical applications (implants, prostheses, valves, stents). Several heat treatments are usually used in order to obtain physical properties required to different applications. This work studied the influence of the heat treatment o...

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Relationship between microstructure and fracture types in a UNS S32205 duplex stainless steel

Duplex stainless steels are susceptible to the formation of sigma phase at high temperature which could potentially be responsible for catastrophic service failure of components. Thermal treatments were applied to duplex stainless steels in order to promote the precipitation of d...

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Effect of α/β Forging on Microstructure and Texture Inhomogeneity in a Ti-1023 Forged Disk

The microstructure and texture distribution of a Ti-1023 forged disk were investigated by scanning electron microscopy and synchrotron-based high-energy X-ray diffraction. The finite element method was used to simulate temperature and strain distribution in order to investigate t...

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Effect of Multi-Pass Bending Deformation on Microstructure Evolution and Mechanical Properties of AZ31 Alloy Sheet

The rolled AZ31 Mg alloy sheets were processed by multi-pass bending (MPB) process at room temperature and followed by annealing treatment. Mechanical properties of the as-received and MPB sheets in annealed conditions were examined based on the concurrent microstructure and text...

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