Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Patryk Wrześniowski"

The interaction characteristics of liquid magnesium and selected magnesium alloys with open-celled glassy carbon foams DOI:10.15199/28.2018.2.3

  1. INTRODUCTION In the last decades, the developments in the technologies of carbon materials have caused new products usable as components in composite materials. In that group, we can find carbon fibers, glassycarbon particles, carbon nanotubes and graphene. At first, they were extremely expensive, but with time, they became cheaper and can be now commercially applied. Among the carbon materials, a new one has appeared, i.e. the glassy carbon open-celled foams (Cof), which, so far, have found applications as a sound absorption material, a biomaterial, a catalyst support or a thermal management material [1÷4]. The Cof are built of cells with walls containing windows and their geometry is commercially characterized by ppi (pores per inch), which means that the pore size increases with a ppi decrease [3, 5÷7]. That type of macrostructure gives the opportunity for carbon foams to be infiltrated by liquid media and to form interpenetrating phase composites [7÷9]. The research works focused on metal matrix composites report that continuous carbon fibers can be infiltrated by magnesium alloys, and magnesium matrix composites with dispersed carbon reinforcements as short fibers, particles and nanotubes can be processed by different powder technologies and casting methods [10÷16]. However, the results of wettability measurements are not unequivocal. If the equilibrium contact angle θ is less than 90°(socalled “good wettability state"), a spontaneous infiltration of molten magnesium into the porous fibres and open-celled preforms can be expected. The contact angle θ between the molten magnesium and the porous graphite as well as the vitreous carbon determined by Shi et al. [17] by the sessile drop method at 700°C in a chamber filled with argon and magnesium vapor was 80° and 74°, respectively. However, the works of other authors [18÷21] showed values higher than 90° as well as poor wettability. The contact angle estima[...]

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