The effect of Ru on gamma' precipitation behavior and evolution in single crystal superalloys with different Ru contents were investigated by scanning electron microscopy with energy dispersive spectroscopy, 3D atomic probing, differential scanning calorimetry. The results show that the solvus of the gamma' phase decreases gradually with increasing Ru content in the alloys by casting or by the same solution and aging treatments, the alloy with a larger Ru content yields a smaller gamma' phase. The addition of Ru increases the growth rate and coarsening rate of the gamma' phase. Ru mainly distributes in the gamma phase, which causes more Re and Mo partition into the gamma' phase, increasing the absolute value of mismatch and the rafting rate of the gamma' phase.

single crystal superalloy; ruthenium; gamma prime; precipitation; growth rate; coarsening rate; mismatch

Shenyang University of Technology; Institute of Metals Research Chinese Academy of Sciences