PhD report (November2011) K. Stan
Tuesday, 6 December, 2011, 11:07 Posted by Katarzyna Stan
Main studies carried out during November: - analysis of the results obtained so far - participation in the European PhD School on "Nanoanalysis using focussed ion and electron beams" – Week 1: "Secondary Ion Mass Spectrometry (SIMS), Transmission Electron Microscopy (TEM), Auger Electron Spectroscopy (AES): a comprehensive overview" organized by Centre de Recherche Public - Gabriel Lippmann w Belvaux, Luksemburg. Lectures presenting an overview of these three analytical techniques were connected with practical sessions in front of the instruments dedicated to each method. - participation in seminar given by MSc. Eng. Pawel Kuczera with the title: „Structure of decagonal quasicrystals Al-Cu-Me (Me = Co, Rh, Ir)”. During seminar following information were given: the problem of thermodynamic stability of quasicrystalline phases, a method of preparing single crystal samples, X-ray diffraction experiments, charge-flipping algorithm
Remember remember the 5th of November
Monday, 5 December, 2011, 15:55 Posted by Jakub Kawalko
November passed quite quickly and almost unnoticeable while I was busy shopping for books and titanium. Also the atmospheric conditions wasn’t making any clues of time passing by, maintaining the impression that we are stuck in late summer rather than falling straight into the jaws of winter. However amidst raging summer and shopping frenzy I managed to read through another portion of literature, paving my way into the temple of PhD grade knowledge. My literature research remains focused on the field of titanium grain refinement by means of plastic deformation methods. While method of equal channel angular pressing (ECAP) is highly developed and described and also can produce satisfying results when combined with other methods of deformation (ex. cold rolling) it exhibits some disadvantages, especially with titanium when substantial grain refinement is desirable. First, titanium has to be heated in order to be plastically deformed in ECAP. Heating of metal during deformation increases recrystallization rates and thus limits maximum grain refinement level. Second, by introduction of large amounts of dislocations and internal stress ECAP makes it difficult to obtain sufficient crystallographic data with good spatial resolution in order to quantitatively characterize nanostructured material. KOBO method (named after inventors: Korbel, Bochniak) resolves some of that problems by change of deformation mode into heterogeneous plastic flow. Change of deformation mode is performed by cyclic change of deformation path (for instance by cyclically reversible plastic twisting ), which leads to destabilization of the structure, and organized dislocation motion. The structure of material is refined by propagating of coarse slip bands and creation of transgranular shear bands. In process no increase of internal stress or dislocation density is produced. There is no literature regarding titanium processed by KOBO method at the moment and performing such procedure involving this metal might indeed produce some interesting results.
November 2011/ Piotr Bobrowski
Monday, 5 December, 2011, 09:49 Posted by Piotr Bobrowski
In the beginning of this month I have visited the Foundry Research Institute. I have discussed details of planned research cooperation. I have also obtained the first sample to do some experiments on it. The work is focused on identification of corrosion processes occurring in seel sample during heating in oxidative atmosphere. Some preliminary measurement have been prosecuted during the rest of the month.
PhD report (November) M. Gajewska
Monday, 5 December, 2011, 09:19 Posted by Marta Gajewska
In November I took part in the European PhD School on "Nanoanalysis using focussed ion and electron beams" - Week 1: "Secondary Ion Mass Spectrometry (SIMS), Transmission Electron Microscopy (TEM), Auger Electron Spectroscopy (AES): a comprehensive overview" held in Centre de Recherche Public - Gabriel Lippmann (Belvaux, Luxembourg, November 14-18) The workshop gave me an overview of the three nanometric analytical techniques - Secondary Ion Mass Spectrometry, Auger Electron Spectroscopy and Transmission Electron Microscopy. Lectures covered: ion and electron interactions with matter, instrumentation and application aspects of these techniques. Apart from the lectures, I also participated in 5 practical sessions (which took place directly in front of the instruments) - each one devoted to the one of the following techniques: Dynamic SIMS, NanoSIMS, AES or Tof-SIMS.
experimental methods for determination of liquid metallic system (MTrybula)
Wednesday, 30 November, 2011, 01:09 Posted by Marcela Trybula
Based on so far experiences, the solution model was used to simulation the physical properties. Firstly it was concentrated on density, later on viscosity. Each of them play significant role in developing a new materials and technology. Knowledge of the density of liquid metals and alloys is crucial in most theories related to the liquid state and the simulation of the contraction that occurs during solidification. There are several methods for measuring the density of liquid metals: pycnometer, maximum-bubble, etc. While, the viscosity is one of the most important transport properties of molten metals. It is related to the internal friction within the liquid and provides some information about the structure of the materials. However, a new experimental method of Roach-Henein enable to simultaneous the determination of three physical properties, namely density, viscosity and surface tension. This new formulation allow to predict flow rate of a stream draining from an orifice under the influence of gravity. Studies was focused on Ag-based liquid alloy.
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