Influence of post ageing on creep behaviour of aluminized Ni-based single crystal superalloy prepared by low-activity high-temperature

• Aluminizing process reduced the creep behaviour of superalloy.
• The coated specimens showed a lower creep behaviour than the bare specimens.
• Post ageing improved the creep behaviour of aluminized superalloy.
• The effect of post ageing on creep behaviour of aluminized superalloy was discussed.

The influence of post ageing treatment on creep behaviour of aluminide coating prepared by low-activity high-temperature on a Ni-based single crystal superalloy was investigated. The results showed that the aluminide coating reduced the creep behaviour of Ni-based single crystal superalloy. The decrease in creep behaviour may be due to the change in microstructures after aluminizing treatment. However, the post ageing treatment at low temperature has successfully improved the creep behaviour of aluminized Ni-based single crystal superalloy. The increase in creep behaviour of aluminized Ni-based single crystal superalloy after post ageing treatment was due to the formation of fine spherical carbides which are distributed in the substrate of Ni-based single crystal superalloy. These fine spherical carbides are able to hinder the dislocation movement and suppress the amount of topologically close-packed phase.