20.500.12556/DKUM-66577 Microstructure analysis of internally oxidized Cu-C composite Mikrostrukturna analiza unutarnje oksidiranog Cu-C kompozita On the basis of experimentally obtained data, it was established that submicron-size bubbles are formed by the internal oxidation of Cu-C composite with fine dispersed graphite particles. They are homogeneously distributed in the Cu-matrix. This process starts with the dissolution of oxygen into the metal at the free surfaces, and continues with the diffusion of oxygen atoms into the volume of copper crystal lattice where they react with the graphite particles. The reactions of dissolved oxygen with carbon yield the gas products (CO2, CO), which cannot be dissolved in the crystal lattice of the matrix. The gas molecules, which are enclosed in the space previously occupied by the graphite, have a greater specific volume than the solid graphite. Consequently, compressive stresses arise in the copper matrix around the bubbles. The interaction of these stress fields with gliding dislocations during loading could improve the mechanical properties of the copper. The internal oxidation kinetic in Cu-C composite depends on the diffusion of oxygen in the copper matrix, and the penetration depth of the internal oxidation front indicates the parabolic nature of the process. Na osnovi eksperimentalnih rezultata utvrđeno je da pri unutrašnjoj oksidaciji Cu-C kompozita s finom disperzijom grafitnih djelića nastaju sub-mi- kronske pore. One su homogeno razpoređene u Cu-matici. Proces počinje otapljanjem kisika na slobodnoj površini metala i nastavlja s difuzijom kisika u kristalnu rešetku Cu-matrice gdje kisik reagira s grafitnim djelićima. Reakcija otopljenog kisika s grafitom daje plinske molekule (CO2, CO) koje se ne mogu rastopiti u kristalnoj rešetki matrice. Plinske molekule koje se nalaze u prostoru gdje je prije toga bio grafit, imaju veći specifični volumen od čvrstog grafita. Posljedično nastaju u matrici oko pora tlačne napetosti. Interakcija ovih napetosti s kliznim dislokacijama pod opterećenjem može poboljšati mehaničke karakteristike bakra. Zapaženo je da je kinetika unutarnje oksidacije u Cu-C kompozitu ovisna od difuzije kisika u Cu-matrici i da penetracijska dubina fronte unutrašnje oksidacije ukazuje na paraboličnu prirodu procesa. metallurgy Cu-C composites internal oxidation bubbles metalurgija Cu-C kompoziti notranja oksidacija pore true false true Angleški jezik Slovenski jezik Znanstveno delo 2017-07-03 13:48:23 2017-07-03 13:49:49 2022-08-01 12:56:04 2019-07-11 15:52:03 2006 0 0 str. 79-84 št. 2 Letn. 45 2006 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1334-2576 669.35'784.018.9:620.186 524301593 10111510 1334-2576 URN:SI:UM:DK:7YJKQY0R Metalurgija_2006_Rudolf_et_al._Microstructure_analysis_of_internally_oxidized_Cu-C_composite.pdf Metalurgija_2006_Rudolf_et_al._Microstructure_analysis_of_internally_oxidized_Cu-C_composite.pdf 1 AEBC4E77F9AA40FDA02002BAA35BE6B3 1e7e665d851f9cbe5ac5f018fa82cb2612f4e2fdd1b7cfce94ca9bf6aca80dfa 56fbcd1f-7c0e-11eb-bb7a-00155d0001ca 20.500.12556/dkum/fc1c92a4-5b6c-4025-92f3-f25aeda7f73b https://dk.um.si/Dokument.php?lang=slv&id=113502 http://hrcak.srce.hr/6514 1 https://dk.um.si/Dokument.php?lang=slv&id=113501 Fakulteta za strojništvo 0 0 0