Microstructure of IC10 superalloy

The microstructures of cast IC10 superalloy are composed of γ′, γ, γ + γ′ eutectics and MC carbides. The volume fraction of γ′ phase is 64 percent, and the MC phase are mainly TaC and HfC, existing in form of spot, Chinese script and blocky. The eutectics show sunflower shape, and γ′ phase spheroidization occurs during the heat treatment. The carbides decompose and wrapps up γ′. After heat treatment there still exist some residual γ + γ′ eutectics. At the grain boundary Hf-rich MC₂ is precipitated. It is found that no harmful TCP phase forms even after aging for 3000 h at 950°C. The microstructural evolution during the aging treatment is characterized by γ′ coarsing and fine HfC precipitation in the inerdendritic area, as well as precipitation of M₂₃C₆ and M₆C phases in small volume along the grain boundary.