图6. 纳米晶304奥氏体不锈钢掺杂La元素后的原子探针和透射电镜表征[58] (b) a bright-field TEM image and corresponding APT Si atom map of a thin slice (5?nm in thickness) reconstructed volume, with 14 resolved nanograins marked as 1-14, respectively and GBs decorated with La-rich nanoprecipitates (NPs). 1D composition profiles across GB5–6, GB6–7, and GB7–8, as marked by green arrows in the Si map, showing the segregation of Si, La, and O at GBs (c) a top magnified combined atom map of Si and La from a small reconstructed region with GBs decorated with La-rich NPs, a bottom combined Fe, Si, and La map of a small framed region of a grain containing a La-rich NP defined by iso-surfaces of 2.5%La (atomic fraction) and fine La-rich clusters. The right proxigrams from La-rich NPs in different sizes reveal their compositions of La-rich NPs at GBs and in grain interiors. The particle size (d) of NPs is defined as the equivalent spherical diameter
|