The paper approach some aspects of the most important parameters that influence the process of extrusion and the quality of material exiting from the die such as extrusion ratio, working temperature ...and speed of deformation. An important advantage gained by using extrusion of high strength aluminium alloys is that different microstructures may be obtained by varying process parameters, such that optimization of processing conditions leads to improved thermo-mechanical properties. Among the multiple process parameters in aluminium extrusion, the extrudate temperature is the most important because it determines the quality of the product and indicates the possibility of increasing extrusion speed.
This paper aims to bring some clarification on grain refinement and modification of high strength alloys used in aerospace technique. In this work it was taken into account 7075 Al alloy, and the ...melt treatment was carried out by placing in the form of master alloy wire ternary AlTiB the casting trough at 730°C. The morphology of the resulting microstructures was characterized by optical microscopy. Micrographs unfinished and finished with pre-alloy containing ternary Al5Ti1B evidence fine crystals, crystal containing no columnar structure and highlights the size of the dendrites, and intermetallic phases occurring at grain boundaries in Al-Zn-Mg-Cu alloy. It has been found that these intermetallic compounds are MgZn2 type. AlTiB master alloys finishing ensures a fine eutectic structure, which determines the properties of hardware and improving the mechanical properties of aluminum alloys used in aeronautical engineering.
The anti-erosion geosynthetic is a three-dimensional element formed of tangled extruded filaments that form a labyrinth structure. It is used for the protection against erosion of the plants and of ...the riverbanks. It has the capacity to protect the soil against being washed away and allows the rapid growth of the roots of the plants.
To determine the influence of the impurities upon elongation at fraction by traction we used a method of mathematical modeling. This is the analysis of regression through active experiment. The ...equation of the elongation of the copper wire in relation with the antimony, arsenic and lead in the copper cathodes is: y'=53,9-2,7 lSb-2,06As -2,29Pb+0,6Sb As+0,44Sb Pb+0,31 As-Pb-0, 3Sb-As-Pb. With the help of a spectrometer we have determined the chemical composition of 27 samples of copper cathodes. Consequently, we have determined the elongation of the copper wire production from these cathodes. This makes the hot deformation impossible. It is important to know the elongation of the wire in relation with the raw material in the process of wire production.
The work presents the study of some thermodynamic properties of the CaO system, which represent the base of several technological processes in the pyrometallurgy of copper. The research have been ...determined several thermodynamic measurements activity and a activity coefficients of oxygen in liquid copper-oxygen function on the temperature and oxygen concentration influence of them. The experimental results have been compared to various thermodynamic models reference to metallurgical melting for alloys and discovery of some structural information on the melting in the studied system.
SOLUTION THERMODYNAMICS AN COPPER-OXYGEN SYSTEM Hotea, V; Iepure, Gh
Scientific Bulletin Series C : Fascicle Mechanics, Tribology, Machine Manufacturing Technology,
01/2005, Volume:
19
Journal Article
This work presents the study of some thermodynamic properties of the Cu-O system, which represent the base of several technological processes in the pyrometalurgy of copper. The research have been ...determined several thermodynamic measurements activity and activity coefficient of oxygen in liquid copper-oxygen function on the temperature and oxygen concentration influence on them. The experimental results have been compared to various thermodynamic models reference to metallurgical melting for alloys and discovery of some structural information on the melting in the studied system. PUBLICATION ABSTRACT
Antierozivni geosintetik je trodimenzionalan element načinjen od spletenih ekstrudiranih vlakana koja formiraju strukturu labirinta. Koristi se za zaštitu biljaka i riječnih obala od erozije. Ima ...sposobnost zaštite tla od ispiranja I omogućava brzi rast korijena biljaka.
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