Scientific blog
PhD report (February 2012) J.Poplewska 
Monday, 5 March, 2012, 13:38
Posted by Jagoda Poplewska
In February, I passed exams of 'Fundamentals of solidification', 'Advanced scanning electron microscopy in materials science' and 'Transmission electron microscopy in materials science'.
I attended in PAS Seminars:
- MSc Eng. Jakub Kawalko: 'The use of methods and optical systems for measuring the stability of photo degradable materials',
- Prof. Antonio G. Checa: 'Multi-level approach to the study of microstructures fabricated by invertebrate molluscs',
- MSc Eng. Adam Debski: 'The enthalpy of formation of inter-metallic phases of lithium-silicon system'.
In that month, I also prepared a draft article under the title: ‘Early stages of recrystallization in ultra fine-grained AA1050 aluminium alloy’:
Abstract
Early stages of recrystallization in aluminium alloys are of considerable practical interest. They were observed for the AA1050 alloy. The samples were processed by equal channel angular pressing along route A up to six passes and then annealed for 1h at different temperatures to obtain different states of recrystallization. Microstructures have been analyzed in sections perpendicular to the extrusion direction, using scanning electron microscopy equipped with high-resolution electron backscattered diffraction facility.
The ECAP-deformed alloy contained a structure of flat grains with the spacing between high angle boundaries ranged from 100nm to 1µm. On annealing, structure coarsened and gets transformed into nearly equiaxed grains. Particular role in the rise of nuclei (at early stages of recrystallization) was attributed to migration of low-angle boundaries and cells coalescence. Later recrystallization stages were attributed to high-angle grain boundaries migration. These processes led to nearly equiaxed grains of similar size. It was documented that length of traces of low- and high- angle boundaries decrease with increasing time of annealing.
The average values of misorientation across both types of grain boundaries systematically grow. Orientation mappings showed that although orientations of new grains were widely scattered, they were not completely random.
Keywords : aluminium alloy, equal channel angular pressing, recovery and recrystallization, microstructure, EBSD

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February 2012 / Piotr Bobrowski 
Monday, 5 March, 2012, 12:15
Posted by Piotr Bobrowski
This month I took part in a training concerning use of the new WDS equipment. It seems that it will be useful in my PhD work since some X-ray peaks from elements in samples received from IOD overlap and are impossible to be distinguished by EDS. Rest of the month was spent on practicing use of the WDS.
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February H. Kazimierczak 
Thursday, 1 March, 2012, 15:09
Posted by Honorata Kazimierczak
In February, I focused on improving of my first scientific publication. I wrote about electroeposition of Sn-Zn and Sn-Zn-Mo layers from citrate solutions. I mainly describe the results of voltammetric studies. My paper has been already reviewed. I hope that my publication will be published soon. Then you will be able to know more about my research :)


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February 
Tuesday, 28 February, 2012, 05:34
Posted by Piotr Drzymala
The goal of my dissertation future will improve the structural properties of magnesium alloys AZ 31 and AZ91, by establishing certain microstructural conditions. The main topic of the paper will examine the impact of thermomechanical strengthening of molded magnesium alloy to improve their properties and processing parameters selection, providing an optimal ratio to improve the mechanical properties of the degree of deformation. This method of treatment is particularly interesting due to the predominant industrial process for producing magnesium alloy by die casting. The elimination of material defects, such as porosity which frequently arise during casting, will extend the use of magnesium alloy for a more responsible construction, for example in the aerospace industry.
In parallel, I dealt with two other issues relating to magnesium alloys. Examination of the previously undescribed magnesium balance of phosphorus will provide information about the suitability of this alloy additive. Planned are also trying to strengthen magnesium alloys - Lithium possible intermetallic phases with magnesium and phosphorus.
Another issue concerning the improvement of formability of magnesium alloy molded plastic processing methods, the use of ultrasound in the manufacture of magnesium. Tensile tests carried out so far samples from the simultaneous operation of ultrasound did not cause softening of the material, however, plans to build a position equipped with a head more powerful.
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EMF study-MTrybula(Feb12) 
Monday, 27 February, 2012, 14:48
Posted by Marcela Trybula
Thermodynamic study of liquid Al-Li-Zn alloys in dependence on temperature, when one and two phase an electrode reference was applied. Calculation of excess thermodynamic functions (Gibbs free energy, entropy, enthalpy of mixing and activity) of lithium. Confrontation the experimental data with a modeled by Guo and the calorimetric study of Kim et Sommer.
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