23 KB257 KB18 KB200020242012Fujda, MartinKvačkaj, TiborMatvija, MilošMilkovič, OndrejNagyová, KatarínaZubko, Pavolletnik:46številka:5str. 465-469ISSN:1580-2949COBISSID:943274URN:URN:NBN:SI:doc-0HH0KEI0enInštitut za kovinske materiale in tehnologijeMateriali in tehnologijealuminijeve zlitinealuminium alloyaluminium alloysECAP ageingmechanical propertiesmehanske lastnostimicrostructuremikrostrukturapressingstaranjestiskanjeStructure and properties of AlMgSi alloys after ECAP and POST-ECAP ageing| Struktura in lastnosti zlitin AlMgSi, staranih pred ECAP in po njem|The mechanical properties and the microstructures of the EN AW 6082 and EN AW 6063 aluminium alloys subjected to pre-ECAP solutionizing heat treatment, equal channel angular pressing (ECAP), and post-ECAP artificial ageing are compared. The quenched alloy states were severely deformed at room temperature by the ECAP technique following route BC. Repetitive ECAP caused formation of the ultra-fine subgrain microstructure with a high dislocation density and high strain hardening of the alloys, thus exhibiting an improvement in strength, but also a degradation of the analysed alloys' ductility. The application of the optimal artificial-ageing regimes after a severe plastic deformation improved only the tensile ductility of the alloys, while their strength was slightly decreased because the softening effect caused by the solid-solution recovery and the relaxation of the internal stress dominated over the hardening effect caused by the expected metastable b''- and b'-Mg2Si phase precipitation during the artificial ageing treatmentPrimerjali smo lastnosti EN AW 6082 in EN AW 6063 aluminijevih zlitin, raztopno žarjenih pred stiskanjem skozi pravokotni kanal (ECAP), po stiskanju ECAP in umetno staranih po ECAP-postopku. Zlitine v gašenem stanju so bile močno deformirane pri sobni temperaturi s tehniko ECAP po poti Bc. Ponovljena ECAP je povzročila nastanek ultra drobnozrnate podmikrostrukture z veliko gostoto dislokacij, velikim utrjevanjem zlitin in s tem povečanje trdnosti ter poslabšanje duktilnosti preiskovanih zlitin. Optimalni režim umetnega staranja po veliki plastični deformaciji je povzročil samo izboljšanje natezne duktilnosti materiala, njihova trdnost pa je bila zmanjšana zaradi učinka mehčanja pri popravi trdne raztopine in sproščanju notranjih napetosti, ki prevladujejo nad učinkom utrjevanja z izločanjem izločkov metastabilne b''- in b'-Mg2Si faze med postopkom umetnega staranjaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije