Actually I have done nothing spectacular this month. I started to work with two example data sets: yttria and nickel superalloy. I spent a lot of time playing with various parameters that can be set in the software for data clean-up and boundary surface reconstruction. I developed a part of computer software for calculating the distributions, but as for now, there is something wrong with them... to be continued next time...

In October I visited Institute for Technical Physics and Materials Science in Budapest. During my stay I had opportunity to perform in-situ heating on thin foil of the multicomponent alloy (with Zr and Mo addition). In this month I also prepared some new alloys by conventional casting. Cast samples were analyzed to determine alloy chemical composition as well as to identify phases present in the alloy microstructure. Additionally I made observation using TEM on samples in as-spun state and after annealing (ex-situ).

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.