Abstract The mechanism of inverse precipitation of γ-like shells forming around primary γ' leading to heteroepitaxial recrystallization after thermomechanical processing was studied. The wrought nickel-based AD730™ alloy was subjected to a sub-solvus heat treatment at 1050°C and cooled at 5°C/min in order to form heteroepitaxial γ-like shells on primary γ'. Electron backscattered diffraction analysis confirmed no measurable crystal misorientation between the γ-like shells and primary γ'. Atom probe tomography revealed segregation of Cr, Co and Fe at dislocations within the primary γ', while the γ-like shell was found enriched in these solutes compared to the γ matrix. A mechanism rationalizing the inverse precipitation of γ-like shells is proposed aiming to better understand the nucleation process of heteroepitaxial recrystallization in polycrystalline Ni-based superalloys.

中文翻译：

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变形镍基高温合金异质外延再结晶的形核机制

摘要 研究了在初生γ'周围形成γ-样壳逆析出导致热机械加工后异质外延再结晶的机理。锻造镍基 AD730™ 合金在 1050°C 下进行亚固溶线热处理，并以 5°C/min 的速度冷却，以在初级 γ' 上形成异质外延 γ 样壳。电子背散射衍射分析证实在类 γ 壳和初级 γ' 之间没有可测量的晶体取向错误。原子探针断层扫描显示 Cr、Co 和 Fe 在初级 γ' 内的位错处偏析，而与 γ 基质相比，发现类 γ 壳富含这些溶质。