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Projects / Programmes source: ARIS

Tehnologije metastabilnih materialov s kovinsko osnovo (Slovene)

Periods
Research activity

Code Science Field Subfield
2.10.00  Engineering sciences and technologies  Manufacturing technologies and systems   
2.04.00  Engineering sciences and technologies  Materials science and technology   
Evaluation (rules)
source: COBISS
Researchers (18)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  17115  Herman Alavančič    Technical associate  2004 - 2006 
2.  10369  PhD Ivan Anžel  Materials science and technology  Head  2004 - 2008  715 
3.  14334  PhD Tonica Bončina  Materials science and technology  Technical associate  2005  400 
4.  20229  PhD Mihael Brunčko  Materials science and technology  Researcher  2004 - 2008  259 
5.  05168  PhD Vladimir Gliha  Manufacturing technologies and systems  Researcher  2004 - 2008  338 
6.  16185  PhD Leo Gusel  Manufacturing technologies and systems  Researcher  2004 - 2008  154 
7.  01375  PhD Janez Kramberger  Mechanical design  Researcher  2006 - 2008  536 
8.  02780  PhD Alojz Križman  Materials science and technology  Researcher  2004 - 2005  773 
9.  11951  PhD Gorazd Lojen  Materials science and technology  Researcher  2004 - 2008  253 
10.  17116  Franc Pernat    Researcher  2004 
11.  12310  PhD Bogdan Pučko  Manufacturing technologies and systems  Researcher  2004 - 2008  50 
12.  19094  PhD Danilo Rojko  Mechanical design  Researcher  2004 - 2005  31 
13.  28409  PhD Niko Rozman  Materials science and technology  Junior researcher  2007 - 2008  36 
14.  14335  PhD Rebeka Rudolf  Manufacturing technologies and systems  Researcher  2004 - 2008  1,094 
15.  09376  Viljem Šprah    Technical associate  2007 - 2008  46 
16.  17123  Rok Šulek    Technical associate  2004 - 2008  79 
17.  24826  PhD Tjaša Zupančič Hartner  Materials science and technology  Junior researcher in economics  2008  85 
18.  12295  PhD Franc Zupanič  Materials science and technology  Researcher  2004 - 2008  483 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0795  University ob Maribor, Faculty of mechanical engineering  Maribor  5089638010  23,900 
Significance for science
Research in the fields of manufacturing, characterization and properties of metastable materials is important for engineering, as well as for the natural sciences (e.g. materials science, physics, chemistry...). Therefore, the results of this research program already gave answers to some open scientific questions, explained the mechanisms of certain processes and phenomena, and initiated the research path into new technologies and materials. Among the open questions there is still the mechanism for plastic deformation of nano-structured materials. It is well-known that the dislocation theory (valid for crystal-structured metals and alloys) does not apply to metastable nano-structured materials. Consequently, the research of these mechanisms is considered as a top-ranking topic of crucial importance for further development in this field. For the science is also important the research and new cognitions about the influence of lattice-defects on the structures of metastable materials regarding the characteristics of chemical reactions and phase transformations in the solid state. Namely, to date research have shown that chemical reactions, which can not be expected in thermodynamically stable microstructures, are definitely possible in metastable microstructures of pure metals, exhibiting increased concentrations of lattice-defects. After the annealing of rapidly solidified copper in a non-oxidative atmosphere, fine dispersed nano-sized oxide-particles were detected. This phenomenon can be considered as a peculiar paradox, because oxidation occurred inside the crystal grains of the pure metal (as a consequence of strongly increased defect-concentration), even though the thermodynamical conditions for this chemical reaction were unfulfilled. For the occurrence and existence of metastable phases a very important issue is the kinetics of their decomposition. There are several theories about the stability of quasi-crystals (e.g. the Pettifor-model) but they do not always explain and predict the formation of quasi-crystals in the multi-component systems. This particularly applies to metastable quasi-crystals. In this case, not only thermodynamical stability but also the kinetics of the processes, taking place at the solid-liquid interface, are very important . Consequently, besides the structure of the melts above and below the liquidus-temperature the mechanisms of homogeneous and heterogeneous nucleation and growth from the liquid phase have been intensively researched. These processes have not as yet been entirely explained, not even for binary systems. So, the presence of a third or fourth element presents an additional challenge. From the literature, as well as from our previous research, it is known that certain elements, e.g. Be, effectively facilitate the formation of quasicrystals in the phase diagram Al-Mn. To date it has been unsatisfactorily explained as to how the presence of Be lowers the free energy (and herewith increases the stability): through decrease of enthalpy of mixing or through increase of the entropy of mixing. We already started to examin the influence of a fourth element which can initiate very interesting interactions between the alloying elements. The research is going to continue in the framework of new programme. With the experiments and analysis of the results we will try to determine: 1) whether an equilibrium solubility of elements in the quasicrystal exists or not; 2) which positions occupy the atoms of individual element in the quasicrystal; 3) if the valence electrons concentration is changed due to the incorporation of additional elements (Hume-Rothery-rule) or, if instead of this, the quasicrystal's composition is modified so that the concentration of the valence electrons can be preserved as unchanged; 4) whether the presence of an additional element influences the size of the quasicell or not.
Significance for the country
In this world numerous research projects are running dealing with the development of technology and materials that are in a metastable state. Moreover, there are a lot of applied projects and the founding of spin-offs and other companies that are concerned with the production of suchlike materials. The added-value of this high tech production is very high. Momentarily, there are in Slovenia, a lot of very successful companies concerned with production, processing, founding of aluminum, copper and noble metals. These companies master the technology of valued alloys, however, they attain poor added-value on the market. To stay competitive in the future they must also be qualified for the production of technologically-advanced materials and products. In these companies those long-term research activities that are important for growth are often disregarded, due to limited financial funds and a few engineers who are occupied with current and short-term problems. From this point of view, we believe that with deeper theoretical knowledge of materials and technologies and also the development and mastering of modern materials technology, we would offer to Slovenian industry solid support in the case of if it being forced to confront the initiation of recent technology and materials.
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