28 KB219 KB26 KB199219991998Križman, AlojzRudolf, Rebekaštevilka:3/4letnik:32str. 185-191ISSN:1318-0010COBISSID:3947030URN:URN:NBN:SI:doc-BI48NDYRslInštitut za kovinske materiale in tehnologijeŽelezarna JeseniceŽelezarna RavneŽelezarna ŠtoreKovine zlitine tehnologijealuminijAluminij Mostaraluminumfazni prehodikompozitimikrostrukturasilicijzlitineAnaliza mikrostrukture kompozitov AlSi7-SiC, izdelanih po postopku tiksotropnega ulivanja| The microstructure analysis of AlSi7-SiC composites made by thixocasting process|Thixocasting is a novel process where the liquid and the solid phse are vigorously stirred. The normal growing of dendrites is hindered and ?$\alpha$? primary globular crystals evolve. Materials produced in this way are very suited for metal matrix composites. By this procedure one achieves better homogeneity and wettability of reinforcement elements. It was found that a variety of ceramic particulates could be added to the semisolid slurry and kept in suspension without floating and settling. This paper deals with microstructure analysis of composites AlSi7-SiC made by the thixocasting procedure. The results show that the homogeneous distribution of SiC in the matrix depends on the volume fraction of SiC, particle size and morphology of SiC, isothermal stirring time, temperature in the semi-solid and cooling velocity from semi-solid to room temperature. The degree of spheroidization of ?$\alpha_Al$? primary grains is strongly influenced by the peresence of SiC elementsPri postopku tiksotropnega ulivanja intenivno mešamo trdno in tekočo fazo v dvofaznem področju, s čimer preprečimo normalno rast dendritov in povzročimo nastanek ?$\alfa$?-globulitnih zrn. Ta postopek se čedalje več uporablja pri izdelavi kompozitov, saj se dodani delci SiC gravitacijsko ne posedajo, prav tako pa ne splavajo na površino taline. Opazimo tudi izboljšanje stopnje omočljivosti ter enakomerne porazdelitve delcev SiC v kovinski osnovi. V tem prispevku podajamo analizo mikrostrukture izdelanega kompozita AlSi7-SiC. Raziskave so pokazale, da je enakomerna porazdelitev delcev SiC v kovinski osnovi odvisna od prostorninskega deleža teh delcev, časa izotermnega mešanja,temperature dvofaznega področja in hitrosti ohlajevanja s temperature dvofaznega področja sobne temperature. Prav tako pa je tudi stopnja sferoidizacije primarne faze ?$\alfa_Al$? močno odvisna od deleža in oblike delcev SiCNadaljuje se kot: Materiali in tehnologijeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije