In May I took part in the "12th European Workshop on Modern Development and Applications in Microbeam Analysis" which was held in Angers, France. I presented a poster there, entitled “3D-EBDS investigation of Ni-Mo protective coatings”. An abstract of the poster contribution is given below. Additionally, I was taking part in 3D-EBSD measurements of a severely deformed aluminum alloy and a Ni-Mo deposit. Some results of these investigations were presented during the conference.

Abstract
P. Bobrowski, M. Faryna and A. Bigos

Hard, wear and corrosion resistant chromium coatings are widely used in aerospace, automotive and machinery industry. Despite of their excellent mechanical properties such coatings are to be eliminated from the manufacturing process due to severe toxicity of hexavalent chromium. A promising alternative to hard chromium coatings are Ni-based coatings containing refractory metals, e.g. Mo obtained from environmentally friendly ammonia-citrate electrolyte. This kind of Ni-Mo coating electrodeposited on steel substrates in a system with the rotating disk electrode under galvanostatic conditions at definite current density 4 A/dm2 was chosen for microstructure investigations. Size, shape as well as orientation of Ni-Mo crystals grown on low carbon stainless steel substrate were established in scanning electron microscope (SEM) by use of three-dimensional electron backscatter diffraction (3D EBSD) technique. It combines a regular 2D orientation imaging microscopy (OIM) with focused ion beam (FIB) sputtering. The FIB consecutively removes successive layers of the material being investigated while the EBSD/SEM acquires electron diffraction data. Such measurements were performed on Quanta 3D FEG SEM with geometrical setup employing rotating pre-tilted sample holder. Experimental parameters and measuring conditions for diffraction acquisition from coating with directionally grown Ni and Mo crystals were evaluated and optimized.

1. Attending in seminars:

- M.Sc. Eng. Sylwia Pawlak: 'The characteristics of stress-textured areas of heterogeneous structure in selected materials and construction elements';
- M.Sc. Eng. Tomasz Kruk: 'Ultra-thin multilayer polymer films as multifunctional coatings and membranes';
- Professor Henryk Paul: 'Inhomogeneity of deformation band and their influence on the formation of deformation and recrystallization textures in fcc metals';

- Associate Professor Piotr Ozga: 'Correlation between ceramics microstructure and functional properties'(second and third meeting);
- Professor Pawel Zieba: ‘Mass and charge transport in polycrystalline materials’ (third meeting);
- Associate Professor Lidia Litynska-Dobrzynska: ‘Development of aluminium alloys’ (third meeting).

2. Training of using the scanning electron microscope for creating maps orientation (EBSD).

3. Research

- Pressing by the curved channel angular (ECAP) the samples of aluminum alloy with dimensions 10x10x70mm using a testing machine INSTRON 3382;
- Preparation of samples for observation in the scanning electron microscope - grinding on abrasive papers, polishing and electrolytic etching;
- Preparation of the orientation maps of samples of aluminum after ECAP and recrystallization (T = 270 ° C and t = 1h, 30 min, 5 min, 2 min, 1 min, 0 min);
- Assisting in the round tensile specimens at elevated temperatures (100 ° C, 200 ° C, 300 ° C) on the testing machine INSTRON 6025.

In May 2011 I continue the study of stability of homogeneous Zn(II)-Sn(II)-Mo(VI) citrate solutions and the study of electrochemical properties of citrate complexes presented in examinated solutions.
The electrochemical behavior of citrate complexes was investigated by cyclic voltammetry method. Cyclic voltammetry (CV) is one of the most commonly used electrochemical techniques, and is based on a linear potential waveform; that is, the potential is changed as a linear function of time. It offers a rapid location of redox potentials of the electroactive species. CV can be used to investigate the electrochemical properties of species.
All my electrochemical studies were carried out with PARSTAT 2273 potentiostat. The working electrode was copper disc, the reference electrode was saturated calomel electrode, and the counter electrode was platinum.
I conducted research in different hydrodynamic conditions, in the following solutions:
1) 0,65 M Na3HCit; pH=5;
2) 0,25 M Na3HCit; pH=5;
3) 0,65 M Na3HCit; 0,02 Na2MoO4; pH=5;
4) 0,65 M Na3HCit; 0,05 Na2MoO4; pH=5;
5) 0,65 M Na3HCit; 0,1 Na2MoO4; pH=5;
6) 0,25 M Na3HCit; 0,02 Na2MoO4; pH=5;
7) 0,25 M Na3HCit; 0,05 Na2MoO4; pH=5;
8) 0,25 M Na3HCit; 0,1 Na2MoO4; pH=5;
9) 0,65 M Na3HCit; 0,08 SnSO4; pH=5;
10) 0,65 M Na3HCit; 0,16 ZnSO4; pH=5;
11) 0,65 M Na3HCit; 0,16 ZnSO4; 0,08 SnSO4; pH=5;
12) 0,65 M Na3HCit; 0,02 Na2MoO4; 0,16 ZnSO4; pH=5;
13) 0,65 M Na3HCit; 0,05 Na2MoO4; 0,16 ZnSO4; pH=5;
14) 0,65 M Na3HCit; 0,1 Na2MoO4; 0,16 ZnSO4; pH=5;
15) 0,65 M Na3HCit; 0,15 Na2MoO4; 0,16 ZnSO4; pH=5;
16) 0,65 M Na3HCit; 0,20 Na2MoO4; 0,16 ZnSO4; pH=5;
17) 0,65 M Na3HCit; 0,24 Na2MoO4; 0,16 ZnSO4; pH=5;
18) 0,65 M Na3HCit; 0,30 Na2MoO4; 0,16 ZnSO4; pH=5;
19) 0,25 M Na3HCit; 0,02 Na2MoO4; 0,16 ZnSO4; pH=5;
20) 0,25 M Na3HCit; 0,05 Na2MoO4; 0,16 ZnSO4; pH=5;
21) 0,25 M Na3HCit; 0,1 Na2MoO4; 0,16 ZnSO4; pH=5;
The results of all carried out tests, and plans for further research were discussed in detail with the tutor Prof. Associate. dr hab. Piotr Ozga.
In May I also attended in the following seminars:
-6.05.2011 roku M.Sc. Eng. Sylwia Pawlak „Charakterystyka naprężeniowo-teksturowa obszarów o niejednorodnej strukturze w wybranych materiałach i elementach konstrukcyjnych” ;
- 27 maja 2011 M.Sc. Eng.. Tomasz Kruk „Ultracienkie wielowarstwowe filmy polimerowe jako wielofunkcyjne powłoki i membrany”.

Main studies carried out during April:

- Microhardness measurements of the Al91Mn7Fe2 ingot. Obtained values were lower comparing to microhardness of melt-spun ribbons prepared from this ingot.
- Further investigations of icosahedral phase decomposition during thermal treatment using TEM and XRD. During I phase transformation nucleation of Al6Mn at the quasicrystal–α-Al phase interface was observed.
- Chemical analyses of all observed phases were done using EDX microanalyser. Information about observed phases obtained by two techniques where compared in relation to the knowledge available from the scientific papers.
- Interpretation of the electron diffraction patterns obtained from observed phases using CaRIne 3.0 crystallographic software.

Participation in seminars:
- M.Sc. Eng. Michal Trebala: “Migration of potassium in potassium ferrite (β-K2Fe22O34) and its application to the surface optimization of catalytic materials”;
- M.Sc. Marcela Trybula: “Applying the theory of free volume for modeling the density and thermodynamic parameters”;
- Prof. Janice M Barton, Prof. Ole Thybo Thomsen: “Nonlinear Thermomechanical Behaviour of Polimer Foam Cored Sandwich Structures”;

Participation in public defense of PhD. thesis:
- M.Sc. Eng. Maciej Szczerba : “Structure and properties of single crystals of magnetic Ni-Mn-Ga alloys”;
- M.Sc. Eng. Anna Maria Janus :”Morphology of natural hydroxyapatite intended for biological applications”.

In april I took part in the 15th Seminar „COMPOSITES 2011 - Theory and practice” (Spala, 27-29 of April 2011). I gave a presentation there entitled “Microstructure and properties of 7475 aluminium alloy matrix nano-composites with 10-20% Al2O3 or AlN additions”.

I am also a co-author of an article which was published under the same title in Composites
(11: 2 (2011) pp. 142-146). Below you can find a short abstract of this article.

MICROSTRUCTURE AND PROPERTIES OF 7475 ALUMINIUM ALLOY MATRIX NANO-COMPOSITES WITH 10-20% Al2O3 OR AlN ADDITIONS
Marta Gajewska, Jan Dutkiewicz, , Lidia Litynska-Dobrzynska, Jerzy Morgiel
Abstract
The microstructure and properties of two types of 7475 aluminium alloy matrix composites - with additions of 10-20 wt. % of nano-Al2O3 or AlN were investigated. The composites were produced through powder-metallurgy processing. Pre-alloyed 7475 aluminium powders were mixed with ceramic particles and milled in a high energy planetary Fritsch ball mill for up to 40 hours. Next, they were compacted at 380°C and 600 MPa. The microstructure of the obtained composites was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The performed investigations proved that both types of composites show a good dispersion of ceramic phases. The composite matrix was characterized by a fine grain size, i.e. less than 100 nm and contained a high density of intermetallic, Zn, Cu or Fe rich phases. The EDX chemical analysis indicated the local presence of an MgO phase at the metal/Al2O3 and metal/AlN interfaces. The microhardness of the compacts were in the range of 315-355 HV and 250-280 HV range for composites with micro-AlN or nano-Al2O3, respectively. It indicates that the size of the nano-crystalline matrix and intermetalic precipitates play a more important role than that of the reinforcing ceramic particles.