Analysis of TIG-Welded Aluminum Alloys During Single Point Incremental Forming at Different Wall Angles

Abstract

In the Tailor-Welded Blanks (TWBs), higher strength or higher stiffness is achieved only at critical areas wherever it is necessary. Many researchers earlier concentrated on TWBs made from steel and its high-strength alloys. Recently, the use of Aluminum alloys has attracted automotive sector in last decade resulted in more research work. In the present study, forming behavior of TWBs made from aluminum alloy AA5052-H32 and AA6061-T6 is studied. TWBs are prepared by joining these two materials with TIG welding technique. These blanks are formed by Single Point Incremental Forming (SPIF) at different wall angles between 40° and 70° with difference of 5°. Formability of the TWBs and parent materials is measured in terms of forming depth, major strain, and thickness strain. The forming result reveals that forming depth of TWBs is achieved up to 12 mm which found to be deteriorated as compared to the forming depth achieved for parent materials (52 mm depth). Further, to find the reason behind this deterioration of TWBs, Slow Strain Rate Tests (SSRTs) are performed for welded portion under very slow straining of 0.0017 mm/min (2.8 × 10^–8 m/s) in air environment. It is observed from the SSRT results that the weld portion and parent blank have shown brittle failure and ductile failure, respectively. This brittle nature of weld is due to the deterioration of TWBs during SPIF process. The proper heat treatment after TIG welding may increase the formability of TIG-welded TWBs.