摩擦撹拌によるAl／Steel異種金属テーラードブランクの強度特性

抄録

The tailor welded blanks between aluminum (Al) alloy, A6061-T6, and stainless steel, SUS304, had been fabricated by a friction stir welding (FSW) technique. The FSW tool was offset to the Al side and the probe was inserted only into Al plate. Hardness, tensile and X-ray CT of Al similar and Al/Steel dissimilar welds had been conducted. Based on the microstructural observation, small steel fragments were recognized in Al side due to the scratching of steel side surface by the probe. The hardness of stir zone (SZ) in Al side was lower than the base metal due to the dissolution of hardening precipitates during welding, where the lowest hardness located near the interface and thermo-mechanically affected zone (TMAZ) in Al side. The tensile strength of the dissimilar weld was about 40% lower than that of the aluminum alloy base metal.