DISSIMILAR FRICTION-STIR WELDING OF ALALLOY 1050 AND MGALLOY AZ31

  • Park, Seung Hwan C. (Department of Materials Processing, Graduate School of Engineering, Tohoku University) ;
  • Masato Michiuchi (Department of Materials Processing, Graduate School of Engineering, Tohoku University) ;
  • Yutaka S. Sato (Department of Materials Processing, Graduate School of Engineering, Tohoku University) ;
  • Hiroyuki Kokawa (Department of Materials Processing, Graduate School of Engineering, Tohoku University)
  • Published : 2002.10.01

Abstract

Dissimilar friction stir welding of aluminum (AI) alloy 1050 and magnesium (Mg) alloy AZ31 was successfully done in the limited welding parameters. The dissimilar weld showed good quality and facility compared to conventional fusion weld. Transverse cross section perpendicular to the welding direction had no defects. The weld was divided into base material of Al alloy, an irregular shaped stir zone and base material of Mg alloy. The irregular shaped stir zone was roughly located around the initial weld center. The weld interface near plate surface shifted from initial weld centerline to the advancing side. Hardness profile of the weld was heterogeneous, and the hardness value of the stir zone was raised to about 150 Hv to 250 Hv. The mixed phase was identified to intermetallic compound $Mg_{17}$Al$_{12}$ using x-ray diffraction method, energy dispersive x-ray spectroscopy (EDX) and electron probe micro analysis (EPMA). The formation of intermetallic compound $Mg_{17}$Al$_{12}$ during FSW causes the remarkable increase in hardness value in the stir zone.one.

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