In March I’ve made a next attempt of in situ production of aluminium/aluminium nitride composites – this time with use of magnetic semi-levitation furnace. AlN reinforment was successfully produced in Al matrix this time as well, but there was no improvement in distribution of ceramic particles (still a lot of agglomerates).This means that I have to start looking for other options.

This month I was preparing to the exam of 'Selected problems of microstructure and texture transformations in deformed metals',
and also preparing the presentation in Power Point tilted:'Influence of zirconium and scandium on microstructural and textural changes of severely deformed aluminum alloys' for the Symposium; 'Materials Science for industry' held in 11-13.04.2013 in Krynica-Zdroj. During the search of the materials in the Internet I have found very interesting web site: http://aluminium.matter.org.uk
This help me to prepare to the exam as well.

April, April showers. The spring is in the water, the spring is in the air. What will April bring. The manuscript of the first paper is almost ready for dispatch.
New alloys are cast and will be homogenized in order to ensure a uniform distribution of elements.
The work in progress!

Lately I obtained silver thin films deposited by magetron sputtering on silicon vafers.
It was found that nanoislands formation is highly sensitive to annealing conditions.
Attempt of examination of importance of layer thickness revealed that inappropriate annealing leads to fingerlike irregular partilces formation.

Another method of fabrication of plasmonic structure is based on surface charge modification followed by nanoparticels adsorption. Silver Nanoparticles in colloidal solution has negative potential which helps to prevent the aggregation process. Modification is based on creation of negatively charged surface and adsorption of polyelectrolyte molecules to change charge into positive.

In my experiments I prepared glass substrate by immersion in NaOH solution followed by HCL and deionised water. Than PAH (polyallylamine hydrochloride)adsorption. On prepared surface I adsorped sub micron copper particles. On surface without preparation no particles was found, on surface specially prepared particles deposited with concentration depended on immersion time.

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.