CAS Key Laboratory of Mechanical Behavior and Design of Materials,University of Science and Technology of China,Hefei 230027,China;
Superalloy Division,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;
Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;
School of Materials Science and Engineering,University of Science and Technology of China,Hefei 230027,China;
Superalloy; Friction stir processing; Grain refinement; Processing parameter;