Hi Dejian,

I guess your question is why the gamma prime solvus temperature of PM Ni-based superalloy is lower than that of the as-cast superalloy?

The PM superalloys possess lower prime solvus temperature due to its low segregation characteristics. For as-cast superalloys, elements Al，Ti，Nb，Ta and Hf, which are gamma prime former, tend to distribute in the interdendritic region (segregation). The quantity and size of r’ in as-cast alloy is larger than PM alloy which resulting in a larger solvus temperature range of the gamma prime for as-cast alloy. Therefore, the final solvus temperature of as-cast alloy is higher than that of the PM alloy which has lower segregation and narrow solvus temperature range.

Dear liang,

Thank you very much for your patient explanation, and I also wonder to know that whether the decrease of the gamma prime solvus temperature leads to the extended durability and the enhanced processability, or other effects in powder metallurgy nickel-based supralloy.

Best regards,

Dejian