Cast aluminium composites with nitride phases
Bolesław Formanek, Maria Sozańska, Marek Staszewski, Mirosław Cholewa, Anna Dulęba 1-3 Politechnika Śląska, Wydział Inżynierii Materiałowej, Katedra Nauki o Materiałach, ul. Krasińskiego 8, 40-018 Katowice, Poland 4, 5 Politechnika Śląska, Wydział Mechaniczny Technologiczny, Instytut Materiałów Inżynierskich i Biomedycznych, Zakład Odlewnictwa ul. Towarowa 7, 44-100 Gliwice, Poland
Quarterly No. 4, 2007 pages 170-175
DOI:
keywords: casting, composite, dispersion, solidification, structure
abstract In this paper technological and material conception of composite manufacturing with use of nitride reinforcing phases, especially aluminium nitride and some results was shown. Composites were manufactured with use of in situ technique with internal reaction from gas phase and ex situ technique - with use of powder metallurgy. In the ex situ technique composite powder addition was used. In powder preparation self-propagation high-temperature synthesis was used. Powders were produced with use of mechanical agglomeration. In in situ technique planned composition was reached by use of chemical--activated allotropic form of nitrogen. Casting were pured into sand and graphite moulds. For ex situ composites required dispersion of reinforcement and matrix crystallization was assisted with external electromagnetic field. Improvement of reinforcing particles distribution can be observed. Composite structure was studied with use of light microscopy, scanning microscopy, X-rays methods and chemical quantitative analysis (EDX) for selected composite micro-regions with high AlN phase content. It was pointed out that composite with regulated reinforcing phase dispersion can be manufactured with alternative use of chemically activated gas generator and powder agglomerates. Advantages of both ex situ and in situ techniques - powder and gas were presented. Electromagnetic field processing positive influence on reinforcing phase distribution and matrix crystallization process was proved. Presented results confirmed justness of assumptions and composite manufacturing conception.