2012 fascicula9 nr2

Investigation of Corrosion Protection by Chemically Applied Patina on Artistic Bronzes

2020-09-03T13:27:38Z

Investigation of Corrosion Protection by Chemically Applied Patina on Artistic Bronzes Sabău (Chelaru), J.D.; Mureşan, L.M.; Soporan, V.F.; Nemeş, O.; Kolozsi, T. Increase of pollution in recent years, requires monitoring of the corrosion behavior of artistic bronzes coated with syntetic patina, in urban atmosphere. This present work aims to investigate the corrosion rezistance of various artificial patina currently used in bronze sculpture. Electrochemical and microscopic methods were used to investigate the protective effect of several chemically produced patinas on artistic bronze. THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI. FASCICLE IX. METALLURGY AND MATERIALS SCIENCE N0. 2 – 2012, ISSN 1453 – 083X

Study for Evaluation and Optimization of Mineral Composition and Structure of Iron Ore Granulation in Sintering Process

2020-09-03T13:27:38Z

Study for Evaluation and Optimization of Mineral Composition and Structure of Iron Ore Granulation in Sintering Process Mogoş, Paul Petruş; Constantin, Nicolae; Ittu, Sînziana; Anca, Denisa-Elena; Harcea, Lavinia-Marilena The characterization of iron ore particles is of vital importance for the study of mineral composition. The specific surface area of iron ore particles can be measured by laser diffraction, and mathematical models (based on the size distribution). Particle size fractions and chemical composition were determined of several types of iron ore (symbolically marked A, B, C, D, E, F). These features have direct influence on the sintering process by particle size analysis, permeability, reducibility, porosity, CaO/SiO ratio, influence of MnO in sinter. The granulation experiment show that these minerals (more than 50% with diameters of <1mm) can be successfully used in the sintering process, or by alloying with other minerals in Europe. Large irregularly shaped and adhesive particles can get a higher efficiency of granulation easily. The usage of iron ore with big and rough particles can improve the permeability while the iron ore with smooth and sphere particles has poor ability of granulation. THE ANNALS OF “DUNAREA DE JOS” UNIVERSITY OF GALATI. FASCICLE IX. METALLURGY AND MATERIALS SCIENCE N0. 2 – 2012, ISSN 1453 – 083X

The Corrosion Behaviour of Aluminum Alloy 2024-T3 in Acidic Environments

2020-09-03T13:27:38Z

The Corrosion Behaviour of Aluminum Alloy 2024-T3 in Acidic Environments Hotea, Vasile; Juhasz, Jozsef; Pop, Elena; Iepure, Gheorghe; Pop, Aurica This research aimed at analysing the acidic corrosion behavior of aluminum alloy 2024-T3 commonly used in the aerospace. We study the variation of corrosion rate with immersion time at different values of H2SO4 concentration and corrosion rate variation depending on the concentration of the solution setting the group of corrosion of the alloy. Aluminum forms initially a few-nm-thick layer of aluminum oxide, γ-Al, which after prolonged exposure in humidified air is covered by aluminum oxyhydroxide, γ-AlOOH, and subsequently by various hydrated aluminum oxides and aluminum hydroxides. The exposed metal surfaces involved aspects of the corrosion process in 0.1M H2SO4, 0.01M H2SO4 and 0.001M H2SO4 solutions, to determine the type of corrosion and propagation mechanism in acidic environments. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 2 – 2012, ISSN 1453 – 083X

Influence of Micro Glass Beads Added in PBT Matrix on the Mechanical Properties of Composites

2020-09-03T13:27:38Z

Influence of Micro Glass Beads Added in PBT Matrix on the Mechanical Properties of Composites Botan, Mihail; Georgescu, Constantin; Deleanu, Lorena This paper presents the influence of adding materials (micros glass spheres) in a matrix of PBT on several mechanical properties: elasticity modulus, stress at break , elongation at break, energy at break. The mechanical properties of these composites depend on the glass beads concentration. The additivation of polybuthylen therephtalate with glass beads increases the values of the elasticity modulus, but reduces quite drastically the elongation at break. Using the SEM investigation, the authors pointed out the particular aspects of fracture surfaces: a ductile process at sample margins and a brittle one in the middle of the composite. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 2 – 2012, ISSN 1453 – 083X