Crystallographic texture and multiscale boundaries mediated creep anisotropy in additively manufactured Ni-based Hastelloy C276 superalloy
参考中译:增材制造的镍基哈氏合金C276超级合金的晶体结构和多尺度边界介导的蠕动各向异性


          

刊名：Additive Manufacturing
作者：Zhijun Qiu（Australian Nuclear Science and Technology Organisation (ANSTO)）
Hanliang Zhu（Australian Nuclear Science and Technology Organisation (ANSTO)）
Zhiyang Wang（Australian Nuclear Science and Technology Organisation (ANSTO)）
Ondrej Muransky（Australian Nuclear Science and Technology Organisation (ANSTO)）
Tao Wei（Australian Nuclear Science and Technology Organisation (ANSTO)）
Elizabeth Budzakoska-Testone（Australian Nuclear Science and Technology Organisation (ANSTO)）
Joel Davis（Australian Nuclear Science and Technology Organisation (ANSTO)）
Andrew Studer（Australian Nuclear Science and Technology Organisation (ANSTO)）
Qinfen Gu（Australian Synchrotron, ANSTO）
Ulf Garbe（Australian Nuclear Science and Technology Organisation (ANSTO)）
David Wexler（School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong）
Huijun Li（School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong）
刊号：780C0044/I
ISSN：2214-8604
出版年：2024
年卷期：2024, vol.83
页码：104069-1--104069-18
总页数：18
分类号：TH16
关键词：Wire and arc-based directed energy deposition；Hastelloy c276 superalloy；Microstructure；Creep anisotropy；Creep mechanism；Microstructure evolution
参考中译：线丝和弧基定向能沉积;哈氏合金c276高温合金;微观结构;蠕动各向异性;蠕动机制;微观结构演变
语种：eng
文摘：The microstructure and high-temperature creep mechanisms of Ni-based Hastelloy C276 superalloy fabricated using wire and arc-based directed energy deposition were investigated systematically and innovatively. The microstructural investigation revealed that the as-fabricated samples comprise γ-Ni matrix and topologically close-packed (TCP) P phase precipitates. The γ matrix subgrains and grains are spread over multiple highly textured columnar dendrites, with a majority of γ <001> crystallographic orientations closely aligned along the deposition direction. Moreover, the interdendritic regions exhibit severe Mo segregation, P phase particles, and dislocation bands. Creep tests were conducted on miniature samples under various temperature and stress conditions, loaded either in the deposition direction (DD) or travel direction (TD). DD samples exhibit lower minimum strain rates, greater strains-to-failure, and longer creep rupture lifetimes than TD samples, indicating significant creep anisotropy. Dislocation creep was identified as the primary creep mechanism for both DD and TD conditions. During creep, dynamic precipitation of TCP phases occurred in the interdendritic regions, resulting in varying creep resistance between interdendritic and dendritic core regions. Isostress and isostrain models, considering both crystallographic texture and precipitation strengthening, reasonably predicted the observed creep anisotropy during the secondary creep stage. Additionally, variations in the Schmid factor led to significant deformation incompatibility among dendrites in TD samples. Dislocation accumulation in TD sample interdendritic regions promoted new grain nucleation, triggering dynamic recrystallisation, facilitating grain boundary sliding, and accelerating tertiary creep. Furthermore, TCP phase particles in the interdendritic regions contributed to microcrack development, further accelerating creep fracture, especially in the TD condition.
参考中译：系统地、创新性地研究了线基和弧基定向能沉积制备的镍基Hastelloy C276高温合金的组织和高温蠕变机制。显微组织研究表明，所制备的样品由γ-Ni基质和拓扑紧密堆积的(TcP)P相组成。γ基体亚晶和颗粒分布在多个高度织构的柱状树枝晶上，大部分γ<001>晶向沿沉积方向紧密排列。此外，枝晶间区域还存在严重的Mo偏析、P相颗粒和位错带。在不同的温度和应力条件下，进行了沿沉积方向(DD)或行进方向(TD)加载的微型试件的蠕变试验。与TD样品相比，DD样品表现出更低的最低应变率、更大的失效应变和更长的蠕变断裂寿命，这表明了显著的蠕变各向异性。位错蠕变是DD和TD条件下的主要蠕变机制。在蠕变过程中，在枝晶间动态析出了TCP相，导致枝晶与枝晶核心区的蠕变抗力不同。等应力和等应变模型综合考虑了晶体织构和析出强化，较好地预测了二次蠕变阶段的蠕变各向异性。此外，施密德因子的变化导致了TD样品中树枝晶之间的显著变形不相容。Td样品枝晶间位错的积累促进了新的晶核，触发了动态再结晶，促进了晶界滑移，加速了三次蠕变。此外，枝晶间的TCP相颗粒促进了微裂纹的发展，进一步加速了蠕变断裂，尤其是在Td条件下。



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