In may I had some more opportunity to exercise with in-situ annealing of titanium samples inside FEG SEM with EBSD capabilities. This time we decided it would be interesting to perform heating with heating ratio similar to one used for DSC measurements and at specific temperatures where we expected something to happen (from DSC results) quickly cool down the sample, measure EBSD map and then repeat for the next temperature. We did as we planned and even with some problems with driting we managed to obtained some decent results. It seems however that this kind of experiment with titanium is strongly affected by surface oxidation which means big problem for diffraction image quality. On the other hand it seems possible that contamination mark on sample surface, created during preceding EBSD scan can have some inhibiting qualities when it comes to oxidation during sample heating.

May was the month extreme full of work. I finally completed writing a dissertation paper. I have done missing EBSD/SEM measurements for recrystallized samples of Al-Zr.
I also passed exams on philosophy and foreign language.

May was dedicated to HUVECs seeding on the surface of variuos samples modified by nanoparticles and 24 bl PLL/HA cross-linked or non-cross-linked films for Impact R assay. I prepared coatings for tribological measurements and PACVD modification for my forthcoming visit in Leoben.

The microstructure inhomogeneity, like group of several adjacent grains cut by the shear bands, is typical for the deformed material (see Fig. 3). Deformation process significantly refines the grains. The area-weighted average grain size of the sample deformed to 13% is ca. 8.3 μm. We observed that the deformation close to the CDL (in the examined alloy ca. 55%) can lead to microstructure with grain size below 2 μm, containing considerable amount of twins.

In this study we adopted the Rodriguez parameterization for description of preferred twin variants in the orientation space. The Rodriguez-Frank orientation space for hexagonal 6/mmm lattice filled with ca. 〖10〗^4 vectors is presented in Fig. 2 [10,11]. The main axes of this coordinate system (R1, R2 and R3) correspond to sample's coordinate system (X, Y, Z). The R1 and R2 values are restricted to range ±1 and R3 is restricted to range ±(2-√3). The presented vectors have minimum length of 0.7 and can be considered as crystallites' orientations transforming sample coordinate systems to crystal ones by the rotations around these vectors by angles between 69.98° and 93.84° [11]. The orientation distribution presented in Fig. 1 is characteristic for extruded hexagonal metals and alloys (like Ti and Mg and its alloys [6,12]).