My research in November:

During the second month of my PhD studies at the Institute of Metallurgy and Material Polish Academy of Sciences I paid attention on preparation of a lecture about “Bioactive glass/poly(L-lactide-co-glycolide) composite scaffolds for bone tissue engineering”. In the second part of the presentation I gave the introduction into biodegradable magnesium alloys. In November I also have made and literature studies connected with biodegradation of magnesium alloys. Together with my supervisor, we have choosen the probable candidate for our research: Mg-Zn-Ca (3-5 wt% Zn, 0.5-1.5 wt% Ca).

Between 14th and 18th of November I participated in “PhD School on nanoanalysis using finely focused ion and electron beams” in Gabriel Lippmann Center in Luxemburg.

In November I studied the stability of homogeneous Zn(II)-Sn(II)-Mo(VI) citrate solutions and theelectrochemical properties of citrate complexes presented in examinated solutions by cyclic voltammetry method and UV-Vis spectroscopy. I conducted research in the following solutions:
1) 0,25 M Cit + 0,02 M Na2MoO4; pH=5;
2) 0,25 M Cit + 0,1 M Na2MoO4; pH=5;
3) 0,25 M Cit + 0,24 M Na2MoO4; pH=5;
4) 0,65 M Cit + 0,02 M Na2MoO4; pH=5;
5) 0,65 M Cit + 0,1 M Na2MoO4; pH=5;
6) 0,65 M Cit + 0,24 M Na2MoO4; pH=5;
7) 0,25 M Cit + 0,02 M Na2MoO4 + 0,16 ZnSO4; pH=5;
8) 0,25 M Cit + 0,1 M Na2MoO4 + 0,16 ZnSO4; pH=5;
9) 0,25 M Cit + 0,24 M Na2MoO4 + 0,16 ZnSO4; pH=5;
10) 0,65 M Cit + 0,02 M Na2MoO4 + 0,16 ZnSO4; pH=5;
11) 0,65 M Cit + 0,1 M Na2MoO4 + 0,16 ZnSO4; pH=5;
12) 0,65 M Cit + 0,24 M Na2MoO4 + 0,16 ZnSO4; pH=5;
13) 0,65 M Cit + 0,24 M Na2MoO4 + 0,08 ZnSO4; pH=5;
14) 0,65 M Cit + 0,24 M Na2MoO4 + 0,32 ZnSO4; pH=5;
15) 0,65 M Cit + 0,24 M Na2MoO4 + 0,16 ZnSO4 + 0,12Na2SO3; pH=5;

My Research:

The main goal was to complete series of studies with scanning electron microscopy using technique - EBSD (electron backscatter diffraction) - creating orientation maps (microstructure) for aluminum alloy AA1050. Unfortunately, my goal was not achieved at 100% due to the time-consuming measurements and the process of preparing samples to the research. I have made several orientations maps: for material in deformed state - after ECAP C6x in cross-sections: ND-TD and the ND-RD; for material in deformed state - after ECAP A6x in the cross-section: ND-RD; and for the initial state in cross-section: TD-RD. Thus, to complete the series of the study with EBSD / SEM left: the initial state in the cross-section: TD-RD and additionally for material in deformed state after ECAP A3x in cross-sections: ND-TD and ND-RD. These studies should be done before the end of the year.

My participation in PAS Seminars:

- Dr Eng. W. Wajda: ‘Simulation of microstructure and texture development using Digital Material Representation and 'Crystal Plasticity’ model’
- MSc. Eng. P. Wyzga: ‘Unconventional methods of producing TiB2-TiN composites’

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

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.