In August, I was mainly writing a paper on boundaries
of special (i.e., tilt, twist, symmetric, and 180-tilt)
in hexagonal materials.
I tried to demonstrate the usefulness of theoretically
obtained diagrams for interpretation of
experimentally obtained grain boundary distributions available in the literature.

Microstructure of grade 2 titanium after KoBo deformation have been investigated. Orientation map have been collected by SEM/EBSD technique from longitudinal cross section of sample. The microstructure differs substantially from one observed in transverse cross section, due to highly anisotropic conditions of KoBo deformation. Curled grains observed in transverse section are replaced by heavily elongated grains in longitudinal section. Elongated grains are grouped in clusters and separated by high angle grain boundaries. Similarly to transverse cross section clusters of elongated grain are accompanied by areas of more strongly refined grains with shapes closer to equiaxed ones.
Similar microstructure have been observed in cold rolled titanium, however there are importatn differences. First are curled grains which are not observed in CR titanium and second are twins which are almost completely absent after KoBo deformation, while in cold rolling are one of most important deformation mechanisms leading to characteristic microstructure.

In August I did:
- microhardness measurement for selected samples of AA3004,
- preparing samples for annealing of Al-Zr,
- continued analysis of global textures measured by X-ray diffractometer,
- preparing a presentation for a meeting summarizing the academic year 2012/2013,
- finished writing and sent the article for the 41th School of Materials Science and Engineering which will be held in 24-27.09.2013 in Krynica (Poland). Below its abstract:

MICROSTRUCTURE AND TEXTURE EVOLUTION DURING ANNEALING
OF AA1050 ALUMINIUM ALLOY PRE-DEFORMED IN ECAP
J. Poplewska, H. Paul, A. Tarasek, K. Berent
Abstract
The main aim of the experiment was to analyze the microstructure and texture evolution during recrystallization of commercial AA1050 aluminum alloy. The samples were processed by ECAP in six passes along route A and then annealed for 1 hour at temperatures ranging from 100°C to 350°C. Studies carried out using scanning electron microscopy equipped with local orientation system and X-ray diffractometer. The obtained results showed that at lower annealing temperatures, the material retains ultra-fine grain structure formed by ECAP. At higher temperatures rapid grain growth appears and transformation of flattened grains into nearly equiaxed was observed. The results showed that obtaining the fine-grained and homogeneous structure of equiaxed grains, is problematic.

Keywords : AA1050 Aluminium alloy; ECAP; Recrystallization; Grain growth; EBSD

Again I tried etched the porous silicon layer and again nothing. So I took the simulations to see how it should be in case of reflectance for textured surface and textured with porous layer. Surprisingly, the real sample reflect less light than the simulated one. Moreover, the porous layer in the simulations worsen the reflectance. You have yet to see it. This must be checked.

I prepared samples with silver nanoparticles obtained by metal island film (MIF) method.
Samples annealed at the 400 Celsius degrees revealed reduction of reflection of Si wafer and change in position of reflection minima due to the change in plasmon resonance for different samples. Highest reflection reduction was obtained for 17 nm initial Ag layer.

By SEM observations average paricles size was found:
120 - 135 nm for inintial 11nm,
130 - 140 nm for initial 14nm,
150 - 170 nm for initial 17 nm,
180 - 200 nm for initial 20 nm.

This corresponds with optical properties of the prepared samples