This month I did some measurements on Crofer 22APU samples. I recieved a new series of samples from Foundry Research Institute. Aditionally I started working on ZrO2 ceramics recieved from AGH Universsity of Thechnology. The ceramics have tetragonal structure that is very close to cubic and its grain size can be tuned by preparation conditions making it an interesting material for basic sturies and practise in 3D-EBSD.

In July i continued preparation and EBSD microstructure investigations of KoBo extruded samples. First just for sport I prepared sample from some aluminum alloy. Preparation compared to zinc and titanium was a breeze and good results was easily achieved, which was nice change after soft hexagonal materials. Microstructure was similar to this obtained in KoBo-ed titanium (grade2) with twisted grains and clearly visible two main directions around which crystals are oriented. Additionally EBSD IPF maps of those samples tend to have some nice artistic feel to them, and this one was not different.
Second one was sample of grade 4 titanium recently extruded by KoBo method. This one was much more difficult to prepare and finaly only smal areas of good surface was obtained for EBSD mapping. Obtained maps look similar to those from KoBo Grade 2 titanium with two main orientations (strong axial texture) of grains and grain sizes close to 5 micrometers.

My research in July:

During the first month of summer holiday I have focused my interest on analyzing all data and writing first article. I have prepared lots of plots, tables and images needed for the publication. Apart from this, some extra evaluation using TEM, SEM and XRD has been done to gather all information necessary for the article.

Probably nobody reads my posts…Anyway, just in case I will write what’s new in my studies performed during June. Days were really hot and sunny but I was sitting inside the Institute building and writing paper “The chemical and thermal stability of the porous coatings for the controlled cell deposition”. It was also necessary to repeat already performed analysis of endothelial cells growth. I prepared series of samples for further FTIR studies. The culmination of the month was an oral presentation “Stem cells encapsulation – therapeutic potential in cardiovascular disease treatment” given on the IInd Symposium “Stem cells – current state of knowledge“, which was held in the Maria Sklodowska –Curie Memorial Cancer Center and Institute of Oncology (Gliwice, 27.06.2012). It concerned possibility of alginate and other hydrogels application in directed delivery of cardiac stem cells into damaged myocardium.

In July I learned about atomic ordering in my alloys and how it may influence the martensitic start transition temperature. Strictly speaking depending on the chemical arrangement of atoms, occupation of lattice sites, there are three possible ordering variants. L21 representative of the Heusler structure in which all atoms in a ternary stoichiometric Heusler alloy X2YZ occupy their designated positions. This gives the full Heusler structure consisting of four interwoven fcc sub lattices. But in reality there is always some degree of chemical disorder influencing many of the physical properties of alloys. When X atoms stay ordered and disorder occurs between Y and Z atoms then we speak about a B2 structure. The third possibility arises when X and either Y or Z sites become disordered which leads to DO3 structure. The type of ordering obviously affects many of the properties as has already been said among them martensite start temperature. Therefore ordering may serve as tool for transition temperature control.