Scientific blog
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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Theoretical study of liquid metals and alloys - MTrybula(August12) 
Monday, 27 February, 2012, 14:38
Posted by Marcela Trybula
Theoretical description of liquid state of metals and alloys, displaying a negative as well as positive deviation from Verlag's law. Construction a new viscosity model for description thermodynamics liquid alloys based on pseudopotentiel theory and MEAM model.
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January 2012 / Piotr Bobrowski 
Monday, 27 February, 2012, 09:59
Posted by Piotr Bobrowski
In the beginning of this month I took part in training concerning new software for 3D EBSD measurements. IT implements some new features. Additionally, it is much easier to use and (at least by now) appears to be more stable. Rest of the month was spent on further training and gaining experience in use of the new software.
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Why fly ashes rock. Some thoughts about my last seminar. 
Thursday, 23 February, 2012, 22:24
Posted by Piotr Drzymala
During the last seminar, on January 20th, I had an opportunity to share with my colleagues the results of the research I did for my engineer’s degree. I earned the degree at the Faculty of Foundry Engineering, AGH University of Science and Technology, though I did most of the experimental work in the Foundry Research Institute in Kraków. Foundry engineering was my second course of study. My educational path was somewhat reversed – I first graduated as a MSc from the Faculty of Applied Mathematics and only after that I got my engineer’s degree.
The title of my diploma thesis was Fly ashes as a component of the reinforcement of aluminium alloy matrix composite. Fly ashes are by-products of the combustion of coal in power plants. They are removed by the dust collection systems from the exhaust gases as fine, spherical glassy particles from the combustion gases before they are discharged into atmosphere. The significance of fly ashes stems from the fact that they are widely used in concrete industry because of their fineness and pozzolanic nature.

The aim of my project was to determine the thermophysical properties. I prepared the samples for testing the temperature characteristics of fly ashes in the form of 3 mm x 3 mm cylinders, compacting the ashes in a special die for sample preparation. I put the samples into apparatus for the determination of characteristic temperatures. For the analysis of the results I used a computer software of PR-25/1750 apparatus, which assists the determination of the temperature of phase transformations.
The results I obtained allowed me to conclude that the production of vitreous materials can be an effective route for recycling of fly ash because the high temperature involved in the process leads to the complete destruction of the organic pollutants. What’s more, heavy metals can be incorporated in the glassy product.

I also carried out experiments on ceramic materials made from fly ashes. I prepared a ceramic called cordierite, which is obtained in the reaction of mullite (contained in fly ashes) with magnesium oxide and silicon dioxide. For that I used fly ashes from different different power plants situated all over the country. The protocol for preparation of codierite was as follows. First, mixture milling was applied for 2-3 h with 2500-3000 r/min, then 10% of glicerine was added, followed by another 10 minutes of milling. The samples were compacted with 20 – 40 MPa pressure and eventually moisture was removed by 3h-long treatment in 100-250°C.

What the cordierite was used for? As the more attentive readers probably have already guessed, I used them for the autoinfiltration process. The procedure was simple. Heat treatment with protective gases in 1350°C for 2.5 h, then immersion of the samples in liquid 7075 Al alloy and finally storing the samples in molten Al alloy in 1000°C for 24h. This treatment allowed me to obtain IPC, which stands for Interpenetrating Phase Composites.

When it came to autoinfiltration, I did not restrict myself to cordierite , but also investigated another fascinating material - ceramic preforms made of cenospheres (particles with a largely empty hollow core). First I immersed the preforms in molten Al alloy (700°C) and kept them there for 7 days. After 7 days I again obtained Interpenetrating Phase Composites (IPC).

That’s all for today. In the near future I will tell you more about my PhD project so stay tuned.

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