Influences of the chill-ring surface on the microstructures and stress rupture behavior of the DD6 single crystal superalloy were investigated.Through comparing with the shinning copper surface and the deposit surface of the chill-ring

the heat radiation ability can be enhanced with spraying carbon on the chill-ring surface

and the temperature gradient is improved.As a result

the primary dendrite arm spacing is decreased

and the angle between the single crystal growth orientation and the[001]orientation is decreased.In addition

the size and volume fraction ofγ-γ′eutectic are reduced

and the stress rupture behabior of the DD6 alloy is improve greatly.