日本金属学会誌
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
論文
単結晶ニッケル基超合金 NKH71 の熱処理と析出 γ′相形態
竹下 貴沖村田 純教三浦 信祐近藤 義宏塚田 祐貴小山 敏幸
著者情報
ジャーナル フリー

2015 年 79 巻 4 号 p. 203-209

詳細
抄録

  NKH71 is a Re free nickel-based single crystal superalloy. The long-term creep strength of this alloy is superior to that of the practical used 2nd generation superalloy, CMSX-4, containing Re but the short-term creep strength is inferior to that of CMSX-4. This may be caused by the initial microstructure before creep. In order to arrange the initial morphology of the γ′ phase in NKH71, eight kinds of processes in heat treatment are carried out. After a series of heat treatments, each specimen is examined with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). From SEM, it is found that the initial morphology of the γ′ phase is different by the cooling rate after solution treatment and temperatures of 1st step aging. It is also found by TEM that dislocation density at the interface between the γ and γ′ phase is different. In order to make clear the origin of the morphological difference in the each heat treatment, the phase field simulation is carried out on the basis of Gibbs free energy calculated using thermodynamic date of Ni-Al binary system.

著者関連情報
© 2015 (公社)日本金属学会
前の記事 次の記事
feedback
Top