JOINING VACUUM HIGH PRESSURE DIE CAST A356 UNDER T4 TREATMENT TO WROUGHT ALLOY 6061

摘要

Vacuum high pressure die cast A356 alloy with T4 solutiontreatment was fusion-joined with wrought alloy 6061 by the GasMetal Arc Welding (GMAW) process. In the present work, themicrostructures of Base metal (T4 A356 and 6061), Heat AffectedZone (HAZ) and Fusion Zone (filler metal ER4043) was analyzedby Scanning Electron Microscopy (SEM) and optical microscopy.The results of tensile testing indicate that the ultimate tensilestrength (UTS), yield strength (YS) and elongation (Ef) of T4A356 are relatively low, compared to both wrought alloy 6061and the filler metal (ER 4043). The microstructure analysis showsthat the reduction in the tensile properties of T4 A356 should bemainly attributed to the lack of strengthening intermetallic phases(Mg2Si) and coarse grain structure, which resulted from T4solution treatment.