Optimization of formability of tailor-welded blanks

Abstract

Nowadays tailor-welded blanks (TWBs) are used in the automotive industries to meet economic concerns, government regulations and design of vehicles with reduced weight and allow cost reduction. This technique is also employed while improving structural integrity and crash performance. Due to the raising environmental concerns about automotive emissions and the scarcity of natural resources, we need to reduce vehicle weight and improve fuel economy. As a result, the automotive industries employ TWBs. In this work, three grades of aluminum sheets (5052, 6061 and 8011) with a 2-mm thickness were made thinner by cold rolling, obtaining three different thicknesses of (0.8, 1.0 and 1.2) mm. Sheets were then joined using the cold-metal-transfer (CMT) welding process. The Taguchi design of experiment (DOE) was carried out for the L27 orthogonal array with nine variables at three levels. Due to this optimization process, the welding decreased the formability of TWBs compared with the parent material and this was reflected in the forming behavior, represented by the strain-distribution profiles. Keywords: tailor-welded blanks, aluminum alloy, incremental forming, cold metal transfer Dandanes se zaradi ekonomi~nosti, vladnih regulativ, dizajna vozil z zmanj{anjo te`o in zaradi zmanj{evanja stro{kov v avtomobilski industriji uporabljajo prilagojeni varjeni surovci (angl. TWBs). Ta tehnika se uporablja tudi zaradi izbolj{anja strukturne celovitosti in obna{anja pri nesre~ah. Zaradi pove~anja okoljskih vpra{anj glede emisij izpu{nih plinov in pomanjkanja naravnih virov, je treba zmanj{ati te`o vozila in izbolj{ati ekonomi~nost porabe goriva. Posledi~no avtomobilska industrija uporablja prilagojene varjene surovce (TWB). V prispevku so bili trije sloji plo~evine aluminija (5052, 6061 in 8011), z debelino 2 mm, stanj{ani s postopkom hladnega valjanja na tri razli~ne debeline (0,8, 1,0 in 1,2) mm. Plasti aluminija so bile nato zdru`ene s postopkom varjenja s kovinskim prenosom (angl. CMT). Taguchijeva metoda na~rtovanja eksperimentiranja (angl. DOE) je bila opravljena za L27 ortogonalno polje z devetimi spremenljivkami na treh ravneh. Iz tega optimizacijskega procesa varjenje zmanj{a sposobnost TWB v primerjavi z originalnim materialom, kar se odra`a v obna{anju formiranj, ki ga predstavljajo profili razdeljevanja sevov. Klju~ne besede: prilagojeni varjeni surovci, aluminijeva zlitina, postopno oblikovanje, hladen transfer kovine