With respect to the studies carried out in August (AFM and profilometer) additional tests were performed using confocal microscopy. The investigations showed that the sample etched in a solution of 8HF:1HNO3:1H2O volume ratio for 60 seconds was characterized by a normal regular surface microstructure consisting of the oval holes ranging in size from a few to tens of micrometers. This means that the resulting structures are considerably higher (approximately twice) than those observed for the wafers etched in the 7:2:1 solution at a the same time. This result can be advantageous from the point of view of the wafers fragility and surface defects etching. The slopes of the resulting holes are smoother while maintaining optimal shape. Holes depth were estimated to a few microns to the maximum of 10.

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.