Solidification Microstructures of a Single-crystal Superalloy under Ultra-high Temperature Gradient Conditions

The solidification microstructures and solute segregation of a newly developed hot corrosionresistant single-crystal Ni-base superalloy were investigated with a zone-melting and ultra-highthermal gradient unidirectional solidification apparatus.Compared with the microstructures solidifiedat conventional low thermal gradient conditions,the dendrite arm spacings,the interdendriticmicroporosity and γ/γ' eutectic,and the severity of solute segregation of the single-crystalsuperalloy solidified at ultra-high thermal gradient conditions were considerably reduced.It wasshown that the microstructure solidified under ultra-high thermal gradient condition is ideal for thefull exploitation of the excellent property potentials of single-crystal superalloys.

Solidification Microstructures of a Single-crystal Superalloy under Ultra-high Temperature Gradient Conditions

The solidification microstructures and solute segregation of a newly developed hot corrosion resistant single-crystal Ni-base superalloy were investigated with a zone-melting and ultra-high thermal gradient unidirectional solidification apparatus.Compared with the microstructures solidified at conventional low thermal gradient conditions,the dendrite arm spacings,the interdendritic microporosity and γ/γ' eutectic,and the severity of solute segregation of the single-crystal superalloy solidified at ultra-high thermal gradient conditions were considerably reduced.It was shown that the microstructure solidified under ultra-high thermal gradient condition is ideal for the full exploitation of the excellent property potentials of single-crystal superalloys.