20.500.12556/RUL-109950 Vpliv staranja na trdoto volframa in volframovega kompozita s karbidnimi vključki Influence of ageing on hardness of tungsten and tungsten composites with tungsten carbide Eden od problemov načrtovanja fuzijske elektrarne je izbira materialov, ki bodo zdržali ekstremne pogoje bližine plazme. Primeren material bi bili lahko volframovi kompoziti. V čistem volframu pri visokih temperaturah poteka proces rekristalizacije, ki jo spremlja rast zrn, kar vodi do poslabšanja mehanskih lastnosti materiala. Potencialna rešitev je kompozit volframa z delci divolframovega karbida (W2C), ki omejijo rast volframovih zrn in s tem zavrejo rekristalizacijo. Pri diplomskem delu sem pripravil štiri zmesi prahov volframa in volframovega karbida (WC) različnih koncentracij. Vzorce sem zgostil s pomočjo tehnike SPS. Z SEM smo analizirali mikrostrukturo in z XRD fazno sestavo vzorcev. Trdoto pripravljenih vzorcev sem primerjal s trdoto istih vzorcev, ki so bili starani. Trdota kompozitov z večjim deležem W2C je višja. Trdota vzorcev pred staranjem in po staranju pri vseh temperaturah je enaka, zato sklepamo, da rekristalizacija med staranjem pri izbranih pogojih ni potekla. One of the problems with designing fusion power plant is the choice of materials that will withstand extreme conditions in proximity of plasma. Suitable materials for this application could be tungsten composites. Pure tungsten starts to recrystallize at high temperatures, where grain growth occurs, and that leads to a deterioration of the mechanical properties of the material. A potential solution is a tungsten composite with ditungsten carbide (W2C) particles that limit the growth of tungsten grains and thus inhibit recrystallization. In my thesis I prepared four mixtures of tungsten and tungsten carbide (WC) powders of different concentrations. The samples were densified using the SPS technique. Microstructure was analyzed using SEM and the phase composition of the samples was determined using XRD. Hardness of the prepared samples was compared with the hardness of the same samples that were aged. The hardness of composites with higher W2C content is higher. The hardness of the specimens before and after aging at all temperatures is the same, so we can conclude that recrystallization in our samples did not occur under the selected conditions during aging. volfram volframov karbid kompozit rekristalizacija staranje trdota tungsten tungsten carbide composite recrystallization aging hardness true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2019-09-10 15:00:09 2019-09-10 15:00:19 2022-08-22 03:40:42 0000-00-00 00:00:00 2019 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 6134 1538422467 Simonic_David_-_Vpliv_staranja_na_trdoto_volframa_in_volframovega_kompozita_s_karbidnimi_vkljuck.pdf Simonic_David_-_Vpliv_staranja_na_trdoto_volframa_in_volframovega_kompozita_s_karbidnimi_vkljuck.pdf 1 9B2C304FBBC84FDD454B6DD1F17D57CA 257f047dc4895077fa9dc686a0e2c0d21bb6c6805428f5fc29bbe8d5f81b43a3 ff589108-a1b6-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=121555 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0