Formation Mechanism of Lamellar M23C6 Carbide in a Cobalt-Base Superalloy During Thermal Exposure at 1000 ℃

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2018,（1）
• 页码范围: 27-32
• 页数: 6页
• 语种: 英文

摘要

The precipitation of the lamellar-shaped M23C6 carbide within the dendritic matrix of a cobalt-base superalloy during thermal exposure at 1000 ℃ has been investigated.Such a precipitation is not commonly observed in cobalt-base superalloys.It is found that M23C6 particles nucleate preferentially at stacking faults (SFs) in the dendritic matrix and grow along the SFs to develop a lamellar character.Additionally,a Cr depletion zone is observed in the vicinity of the lamellar M23C6 carbide,which strongly supports the presence of Suzuki segregation.