title: Microstructure of a newly developed gamma' strengthened Co-base superalloy.
abstract: The microstructure of a newly developed Co-base superalloy with enhanced high-temperature strength has been investigated using transmission electron microscopy (TEM) and three-dimensional atom probe (3DAP) techniques. It mainly consists of a typical gamma/gamma' (FCC/L1(2)) structure and a plate-shaped AB3-type (Ni,Co,Cr)3(Ti,Al) intermetallic compound with hexagonal structure (a approximately 5.1A and c approximately 12.5A). gamma' is formed with a bimodal distribution and fine gamma' has a cuboidal morphology. Cr and Co are enriched in the gamma phase, while Ti, Al and Ni are enriched in the gamma' phase. W and Mo are more or less uniformly distributed in both gamma and gamma'. Chemical composition analysis by 3DAP suggests that the plate-shaped phase has a higher Ti and lower Al content compared to that of gamma' phase, and the concentration of Ti, Co and Ni has a periodic variation along c-axis with a period of 12.5A in the plate-shaped phase.
authors: High Temperature Materials Center, National Institute for Materials Science, Sengen 1-2-1, Tsukuba 305 0047, Japan. PING.De-hai@nims.go.jp
authors: D H
authors: DH
authors: Ping
authors: C Y
authors: CY
authors: Cui
authors: Y F
authors: YF
authors: Gu
authors: H
authors: H
authors: Harada