材料期刊网

Formation of Re-containing Carbides in a Second Generation Directionally Solidi¯ed Ni Base Superalloy

Tan Zhao , Dong Wang , Jian Zhang , Guang Chen , Langhong Lou

材料科学技术（英文）

The precipitates at grain boundary in a directionally solidified Ni base superalloy after heat treatment, aging at 975°C, and creep rupture test have been characterized. Besides the primary MC carbides and fine particles of  μ phase, the Re-containing M₂₃C₆ was observed. The precipitation kinetics revealed that the formation of M₂₃C₆ was associated with the dissolution of μ phase and MC carbides. TEM image shows that the continuous precipitation of M₂₃C₆ particles effectively hinders the dislocation  movement and strengthens the grain boundaries. The high strength of the alloy suggests that M₂₃C₆ carbides are beneficial to the properties although Re as an important matrix strengthening element was consumed.

关键词: Ni-base Superalloys , null , null , null