In October I decided to change a production route of my in situ Al/AlN composites. As a solid state reaction method hasn’t really worked out, I decided to switch to liquid state reaction (but still with a use of magnesium nitride as a nitrogen-bearing medium).

I also visited the Institute for Technical Physics and Materials Science of Hungarian Academy of Sciences where I managed to perform some TEM in-situ heating investigations of precipitate dissolution in my composites produced via powder metallurgy route.

During October I was trying to investigate Al6013 sample. It was processed using the KoBo method. I was trying to collect EDS data along with EBSD. First try was unsuccessful because of unknown software error which resulted in stopping of the experiment. During the second try, a microscope failure occurred, the software lost control over the EBSD camera. Additionally, vacuum system failed and it was impossible to obtain sufficient vacuum level to carry any measurements. Finally, at the oend of the month I managed to run a successful measurement. It was the longest experiment carried out so far, ROI dimensions were 30x30x30um and a voxel size was 100nm in each direction. The measurement took ca. 58 hours.

My research in October:


The article entitled "Investigation of structures in as-cast alloys from the Mg-Zn-Ca system"
was sent to Achives of Materials and Metallurgy

Here you can read abstract:

Alloys of nominal composition Mg-3Zn-xCa (x = 0, 0.2, 0.5, 0.7, 1.0, 1.3) wt.% have been prepared by resistance melting and casting into graphite mould under argon atmosphere. All investigated alloys have revealed (Mg) dendritic microstructures with intermetallic phases distributed in interdendritic spacing. The Mg4Zn7 has been identified as the main phase which coexists with (Mg) in the Mg-Zn alloy. Calcium addition causes the formation of ternary Ca2Mg6Zn3 hexagonal phase, denoted also as Ca3MgxZn15-x. The increase of Mg/Zn ratio from 0.59 in Mg-3Zn-0.2Ca wt.% alloy to 2.72 in Mg-3Zn-1.3Ca wt.% alloy in this phase is connected with an increase in the lattice parameters. The microhardness of the Ca containing alloys increases up to 67 HV (for the alloy containing 1.3 wag.% Ca) compared to the 50 HV for Mg-3Zn wt.% alloy.

In October I’ve studied the electrodeposition process. I lead the process of potentiostatic deposition of Zn-Mo alloy layers, on the steel and copper surfaces, from stable homogeneous Zn(II)-Sn(II)-Mo(VI) and Zn(II)-Mo(VI) citrate baths, in the slightly acid range (pH about 5), with different concentration of metals and citrate ions. The measurements were performed in a three-electrode cell or galvanostatically in a two-electrode cell in coulostatic condition, by means of potentiostat PGSTAT302N.

Management of the molecular dynamic simulation for liquid Al-Zn alloys in order to model the transport properties using Yukawa and EOPP potential. Random mixing and PBC condition was used to simulate the viscosity and diffusion coefficient.