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Year 2004 No 1

Kvačkaj T., Besterci M., Balloková B.
ULTRAFINE STRUCTURE FORMATION IN COMPOSITE MATERIAL Al-Al4C3
Abstract
In the present research work was searched the influence of severe plastic deformation (SPD) realized by ECAP procedure on structural, mechanical and plastic properties of Al-Al4C3 composite material. The ECAP process doesn’t influence samples shape and sizes and produced ultrafine nanocrystalline structures. Following composite material was prepared by mechanical alloying. Composite granulate was extruded in die with 94% reduction at temperature 550°C. Extrusion in ECAP die was made at ambient temperature. Severe plastic deformations were effected the increase of strength properties (Rm, Rp0,2 ).Strength properties were increased from 1.3 till 1.4 multiple, but plastic facilities were decreased and hardness was risen, in comparison with initial material state. The great decrease was searched in grain size diameter, where diameter of grain size was decreased from initial value 1 ?m up to ultrafine level 0.6 ?m after ECAP deformation. The change in grain size diameter was made by redistribution of dislocation substructure and deformation slips in initial grain. Valuation of fracture surfaces was mentioned on their large segmentation. The fractures were classified look like transcrystalline ductile fractures with two quantitative ranks of holes. Small holes with diameter bellow 1 ?m they were initiatives by Al4C3 elements, where had size up to 200 nm. Large holes with diameter above 2 ?m were results of sizeable elements initiation, or clustering of small elements, resp. residual pores. With ECAP procedure in investigation Al-Al4C3 composite material samples was achieved ultrafine nanostructure at level 0.6 ?m.

Keywords: ultrafine nanostructure|severe plastic deformation|material properties|ECAP methods|
No 1 (2004), p. 5-9
  mag01.pdf (387 kB)
mag01_eng.txt (2 kB)  

Jelínek P., Polzin H., Škuta R.
UTILIZATION OF PHYSICAL DEHYDRATION FOR HARDENING OF CORES BONDED WITH COLLOIDAL SOLUTIONS OF ALKALINE SILICATES
Keywords: additived Na-silicates|microwave hardening|Hot-Box process|shelf life and collapsibility of cores|modulus and structure 29Si NMR|water distributi
No 1 (2004), p. 10-23
  mag02.pdf (452 kB)
mag02_eng.txt (2 kB)  

Khouri S., Horodníková J., Domaracká L., Vodzinská V.
MANAGEMENT OF MINING COMPANY BY USAGE OF MANAGEMENT INFORMATION SYSTEM
Keywords:
No 1 (2004), p. 24-28
  mag03.pdf (217 kB)
mag03_eng.txt (1 kB)  

Sofilić T., Barišić D., Grahek Ž., Cerjan-Stefanović Š., Rastovčan-Mioč A., Mioč B.
RADIONUCLIDES IN METALLURGICAL PRODUCTS AND WASTE
Keywords: radionuclide distribution|steel|slag|dust|
No 1 (2004), p. 29-35
  mag04.pdf (227 kB)
mag04_eng.txt (831 B)  

Seilerová K. , Mihok Ľ., Domovec M., Balco K.
INFLUENCE OF LADLE FURNACE Ar STIRRING ON STEEL CLEANLINESS
Keywords: Ladle furnace|Cleanliness of steel|Stirring|
No 1 (2004), p. 36-41
  mag05.pdf (334 kB)
mag05_eng.txt (819 B)  

Kaytbay S. H. M., Dudrová E.
CONTRIBUTION TO ANALYSIS OF COMPACTION OF METAL POWDERS
Keywords: powder metallurgy|powder compaction|quantification of compaction processes|
No 1 (2004), p. 42-48
  mag06.pdf (223 kB)
mag06_eng.txt (1 kB)  

Pietriková A., Búgel M., Buršák M., Neubauer M.
PREPARATION TECHNIQUE OF SILICONE DIOXIDE SIO2 FROM WASTE DUMP BASED ON SERPENTINE
Keywords: silicone dioxide|serpentine|asbestos|leaching|
No 1 (2004), p. 49-58
  mag07.pdf (506 kB)
mag07_eng.txt (4 kB)  

Drápala J., Kuchař L.
DISTRIBUTION COEFFICIENTS OF ADMIXTURES IN TIN
Keywords: Distribution coefficient|tin|binary systems|
No 1 (2004), p. 59-66
  mag08.pdf (388 kB)
mag08_eng.txt (439 B)