Pt+g ￠-Ni3Al+g-Ni/CMSX-4涂层结构的透射电镜研究

TEM Characterization of Pt+g ￠-Ni3Al+g -Ni/CMSX-4 Coating Microstructure

摘要:

通过在CMSX-4镍基单晶高温合金表面镀Pt然后采用包埋渗铝的方法成功制备Pt改性的Pt+g ￠-Ni3Al+g -Ni/CMSX-4涂层，采用扫描电镜和透射电镜研究Pt+g ￠-Ni3Al+g -Ni/CMSX-4涂层的微观结构。TEM分析表明Pt主要分布于涂层g ￠-Ni3Al相中，且涂层g ￠-Ni3Al相里存在 {111} 孪晶；此外涂层内还发现六方结构富铼的拓扑密堆相（m相），点阵常数为a = 0.473 nm和c = 2.565 nm，首次发现m 相内除了（001）孪晶外还存在（10

关键词:g ￠-Ni3Al+g -Ni涂层;TCP相;孪晶;透射电镜

Abstract:

Pt+g ￠-Ni3Al+g -Ni/CMSX-4 coatings were fabricated by Pt electroplating on CMSX-4 single crystal superalloys substrate and followed by an aluminizing pack cementation process. The microstructure of the Pt+g ￠-Ni3Al+g -Ni/CMSX-4 coating was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM investigation showed that {111} twinning exists in the g ￠-Ni3Al phase, Pt was mainly distributed in the g ￠-Ni3Al. Precipitates were observed in the coatings. Selected area electron diffraction (SAED) reveals that the precipitate was the hexagonal topologically close-packed (TCP) m phase with lattice parameters a=0.473 nm, and c=2.565 nm. Twin domains parallel to (001) and (10

Key words:g ￠-Ni3Al+g -Ni coating; topologically close-packed (TCP) phase; twinning; transmission electron microscopy