J Mater Sci Technol ›› 2009, Vol. 25 ›› Issue (03): 351-355.

• Research Articles • Previous Articles     Next Articles

Effect of Y Addition on Microstructure and Mechanical Properties of Friction Stir Welded ZK60 Alloy

G.M. Xie1,2)†,  Z.Y. Ma2)†, L. Geng1)   

  1. 1) School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
    2) Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2008-05-04 Online:2009-05-28 Published:2009-10-10
  • Supported by:

    the National Outstanding Young Scientist Foundation under Grant No. 50525103
    the Hundred Talents Program of Chinese Academy of Sciences

Abstract:

6 mm thick ZK60 and ZK60-Y alloy plates were successfully friction stir welded (FSW) at a tool rotation rate of 1200 r/min and a traverse speed of 100 mm/min. FSW resulted in the dissolution of MgZn2 particles in the ZK60 and the breakup and dispersion of W-phase (Mg3Zn3Y2) particles in the ZK60-Y alloy, thereby leading to a decrease in the hardness of the nugget zone (NZ) for the ZK60 alloy and an increase in the hardness of the NZ for the ZK60-Y alloy, respectively. While two FSW joints exhibited similar joint efficiency (87%{89% of ultimate tensile strengths of the parent materials), the yield strength of the FSW ZK60-Y joint was substantially higher than that of the FSW ZK60 joint. The fracture occurred in the NZ and the heat affected zone for the ZK60 and ZK60-Y joints, respectively, which were consistent with the lowest hardness distribution of the welded joints.

Key words: Friction stir welding, Magnesium, Microstructure, Mechanical properties