Analiza mikrostrukture i svojstava zavarenog spoja aluminijske legure EN AW-5083

Cilj ovoga rada bila je analiza zavarenog spoja legure aluminija oznake EN AW-5083. To je gnječena legura aluminija s najvećim udjelom magnezija kao legirnog elementa. Zavareni spoj izveden je TIG tehnikom spajanja uz prethodno predgrijavanje na 150 °C. U teorijskom dijelu obrađene su vrste aluminija i njegovih legura te načini zavarivanja istih. Objašnjene su moguće pogreške koje se mogu pojaviti tijekom ili nakon zavarivanja. U eksperimentalnom dijelu rada analizirana je makrostruktura zavarenog spoja, te mikrostruktura osnovnog materijala, zone utjecaja topline i metala zavara. Osim toga provedeno je ispitivanje mikrotvrdoće HV0,2, statičko vlačno i savojno ispitivanje. U strukturi nisu uočene nikakve nepravilnosti koje bi negativno utjecale na kvalitetu zavarenog spoja. U odnosu na mikrotvrdoću osnovnog materijala (oko 68 HV0,2), mikrotvrdoća u ZUT-u i metalu zavara je viša za oko 20 %.Vrijednost vlačne čvrstoće u osnovnom materijalu je 330 MPa, a u metalu zavara 280 MPa. Tijekom savojnog ispitivanja do kuta od 180° nisu uočene pukotine u zavarenom spoju. The aim of this work was the analysis of the welded joint of aluminum alloy EN AW-5083. It is a wrought aluminum alloy with the highest proportion of magnesium as an alloying element. The welded joint was made using the TIG joining technique with preheating to 150 °C. In the theoretical part, the types of aluminum and its alloys and methods of welding them are covered. Possible errors that may occur during or after welding are explained. In the experimental part of the work, the macrostructure of the welded joint was analyzed, as well as the microstructure of the base material, the heat-affected zone and the weld metal. In addition, a microhardness test of HV0.2, a tensile and bend test, was performed. No irregularities were observed in the structure that would negatively affect the quality of the welded joint. In relation to the microhardness of the base material (about 68HV0.2), the microhardness in ZUT and weld metal is higher by about 20%. The value of the tensile strength in the base material is 330 MPa, and in the weld metal 280 MPa. During the bending test, no cracks were observed in the welded joint up to an angle of 180°.