August is very hot this year in Kraków and I’m spending it on the preparation of Zn-Mo alloy samples for the corrosion tests. I need dozens of samples for corrosion test, so my work in August is very important but also tedious and monotonous.

This month I was focused on finishing writing of a publication. It is entitled “Investigation of grain boundaries geometry and pores morphology in dense and porous cubic zirconia”. Below I attach an abstract:
Three-dimensional orientation microscopy was used for visualization of grain boundaries geometry and pores morphology in cubic zirconia stabilized with 8mol% of yttria. Set of four samples sintered at different conditions was investigated. Specimens were characterized by EDS and XRD techniques showing that they were entirely composed of cubic phase. Investigations of boundaries and pores structure were carried in dual-beam scanning electron microscope. For each studied sample, dimensions of the region of interest were 10μm in each direction. Analysis of grain boundaries networks reconstructed from inverse pole figure maps revealed strong dependence between grain boundary density and samples preparation parameters. Sintering also affects pores size and their distribution. The total amount of analyzed grains varied from 13 to 190 and calculated volume of cavities was changing between 0.01% and 25%. Present paper shows the capabilities of three dimensional crystallographic orientation analysis applied to ceramics dedicated to solid oxide fuel cells production.

As Summer stepped in, a pace of my work slackened significantly. I managed to perform some TEM investigations of a thin foil of in situ Al/AlN composite, which I have recently cut out using FIB technique, and, in search of a remedy for very poor distribution of AlN reinforcement in aluminium matrix, I went through few papers concerning in situ formation of reinforcement in metal matrices.

The failure of the previous month did not discourage me too much. Reagents cooling in the fridge was failed so I put them into a freezer. All reagents, except water, have a melting point of about -30 degrees C. The result - great! The mixture had cooled to a temperature slightly below zero. Texturization took place in the same reaction mixture during slowly heating in temps: 0, 5, 10, 15, 20, 25. The best result I reached for the wafer etched in solution HF:HNO3:H2O = 8:1:1 in 5 C. Surface was smooth, uniform and black.
In the case of nanoporous layer etching I found that I used too strong solution, 3M KOH instead of a 1M. The experiment should be repeated.

Tthe data of EBSD maps of pipe AZ31 magnesium alloy was processed. The purpose of the data analysis was to find evidence to secondary slip systems other special type of locally rebuild lattice inside of grains, called twinning. It was also shown by the way, that used in our laboratory formula of calculation orientation from the (hkl) <uvw> form only works for the cubic network, and therefore the application was written which calculates the matrix in the correct manner for any orientation of the (hkl) <uvw > in the hexagonal system.
To describe any disorientation, one inputs for the two orientations, given eg. by Euler angles, rotation matrices to calculate the passive g1, g2. Then you come up with a lattice symmetry operators. In a hexagonal network of 12, which means that for any orientation, there are 11 consecutive orientation which are set in the configuration of elementary cell indistinguishable in terms of physical properties and also for the human eye. We use left side symmetry operators, call it O. Thus each orientation symmetric matrix is expressed as the overall to get all the combinations of two possible orientations in the hexagonal lattice: O.g1.(O.g2^-1) which is equivalent to O.g1.g2^T.O. Of course we have to add the case: O.g2.g1^T.O to get all 12*2*12 possible combinations. But that's not all, you now need to simplify further considerations, bringing combinations to the area of a given base. This is not a trivial task, as long as we do not know the Rodriguez parametrization and shapeof the fundamental zone of the crystal lattice. In the case of a hexagonal network fundamental zone looks like a piece of cake.