24 KB291 KB23 KB200020242004Bizjak, MartinKoprivšek, MitjaKovač, Janezštevilka:1/2letnik:386 stranistr. 123-128ISSN:1580-2949COBISSID:344234URN:URN:NBN:SI:doc-C8N8NK9OslInštitut za kovinske materiale in tehnologijeMateriali in tehnologijebakerfazni diagramikositermetalografijapreiskava materialataliljenjevarovalkePojavi na talilnem elementu varovalke v talilni fazi izklopa|Test samples of melting fuses rated for a current of 63 A were subjected to tests with a breaking current of 100 A, where the melting of the fuse element is the principal process of current interruption. Particular sites of the fuse element strip, notches, are coated with an alloy with a low melting point and in this way they enable the break of the overcurrent by melting and dissolving the base Cu strip. The investigation of the fuse elements was performed after the break tests and involved optical microscopy, metallography, SEM and EDX microanalysis of the chemical composition. Results were analyzed using binary diagrams of Cd-Sn, Cu-Sn and Cd-Cu. The effects of phenomena which occasionally prolong the melting process were investigated in order to reduce excessive heating of the fuse link during the break. As a prolonged type of melting phase could be thermally harmful to the adjacent plastic parts of insulation, measures to avoid it are important for the design of the fuse element and its manufacturing technologyNa talilnem vložku varovalke za nazivni tok 63 A je bil izveden preskus izklopa toka 100 A. V teh razmerah pride do prekinitve toka v varovalki med talilno fazo, ko se na talilnem elementu stalijo perforirani segment na prekinitvenih mestih, kjer je nanesena plast nizkotaljive zlitine. Po preskusu je bil talilni element preiskan z optično mikroskopijo, metalografijo, elektronsko mikroskopijo in elektronsko mikroanalizo. Za presojo rezultatov so bili uporabljeni binarni diagrami za pare Cd-Sn, Cu-Sn in Cd-Cu. Ugotovljeni so bili vzroki, ki včasih usmerijo potek izklopa v podaljšano talilno fazo, namesto da bi se končal z normalno, v kateri učinki izklopa niso nevarni za bližnjo okolico. Kako te vzroke odpraviti s spremembo konstrukcije talilnega elementa ali tehnologijo izdelave, je pomembno za proizvajalca varovalkTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije