Main studies carried out during the month:

- using new equipment – vibration micromill, melt spun ribbons of ternary alloy Al-Mn-Fe were pulverized into powder. Two trials were performed on alumina and tungsten carbide balls and containers
- melt spun ribbons with hafnium addition were annealed to precipitate hafnium from the solid solution which could lead to strengthening of whole sample.
- microstructure of cast alloys (containing five or six elements including molybdenum and zirconium or molybdenum and hafnium) was studied using SEM. All investigated alloys revealed similar microstructure including presence of phases like Al6(Mn,Fe), Al3(Mn,Fe) and Al3(Hf,Zr,Ti).
- using SEM melt spun ribbons pulverized with vibration mill were investigated after different times of milling. In obtained powders two fractions were observed: one with big particles around 200 µm and second one with particles below 20 µm. This indicates that longer time of milling is necessary as well as selection need to be performed to separate different fractions.

This month I have carried out some SEM observations on titanium surface treated by electroerosion machining. Method of electroerosion allows for very precise shaping of material by its removal in a very controlled manner. During the process material submerged in dielectric liquid and high voltage is applied between the material and special electrode. By controlling voltage and space (gap) between material and electrode, electric discharge is created. During the discharge in the gap a plasma tunnel is created that conducts electricity, but also releases high amounts of energy. This energy is turned into temperature (up to 4000 C). During that discharge material is rapidly melted and ablated. After the discharge ends, plasma tunnel breaks down, and rapidly implodes washing away melted material.
This type of machining was chosen as a possibility for producing parts of implant-distractor. Therefore its impact on titanium surface layer properties and morphology is being studied.

During this month I faced some technical problems with the microscope. The sample stage was not working as it was supposed to. Especially, rotation of a sample was often impossible due to encoder errors. This made running of 3D measurements impossible. Meanwhile, I read some literature concerning investigations of the cubic ZrO2 where I found information about methods that other people use for sample preparation and what programs are used for experimental data processing.

In the meantime, texture measurements were made on the extruded pipe section and further pilger rolled and extruded alloy AZ31 in three spots. Measured reflections 002, 101 and 100 and the orientation distribution functions were calculated for the three points. Since the program LaboTex automatically narrows the field of orientation function (Euler space) in the case of higher symmetry than triclinic and there is no way to save the functions of a full field, you had to work around this problem in a sophisticated manner described in the literature. After completion of the orientation function to generate a SOR of individual orientations in a large number (in our case 2000000). Then you need to change the structure of the code editor to 1 (symmetry triclinic) and open the converted file in the LaboTex. Now you just need to generate the orientation distribution function on the basis of individual orientation, so that we skip the tedious process of symmetrization orientation distribution function, of course, at the expense of extra work.

In March I’ve worked on my next publication. It is titled “Characterisation of Zn–Mo alloy layers electrodeposited from aqueous citrate solution”
In this paper I wrote among others that: The conditions for molybdenum with zinc electrodeposition from citrate electrolytes were studied. Partial polarisation curves were determined. The surface composition of deposits was ascertained by chemical analysis (EDS and WDXRF) and profile chemical analysis (GDOES). The morphology of coatings was
studied by SEM. The electrolysis parameters allowing electrodeposition of homogeneous Zn–Mo coatings containing various amounts of molybdenum (in the range from about 0.5 wt.% to 8 wt.%) were selected. The deposits’ morphology depends significantly on the content of molybdenum and on the substrate used. Two Zn–Mo phases are formed in deposits: a hexagonal phase with low content of molybdenum, and an amorphous or nanocrystalline phase enriched by molybdenum.