高级检索

选区激光熔化γ″强化镍基高温合金热处理调控与力学性能研究进展

Research progress on heat treatment regulation and mechanical properties of selective laser melted γ″-strengthened nickel-based superalloys

  • 摘要: 激光增材制造镍基高温合金复杂非平衡凝固组织的热稳定性与传统铸态、锻态不同,使得采用传统标准热处理工艺无法获得增材制造合金的稳定组织和优异性能。因此,亟需明晰增材制造非稳态热循环过程中亚稳态析出组织特征与热处理工艺之间的内在关联,理解亚稳态组织热处理过程中的晶粒生长、第二相析出、位错演变等行为。本文以航空发动机及燃气轮机领域广泛应用的γ″强化镍基高温合金(IN718 alloy)为研究对象,综述了其选区激光熔化成形后的组织特征,讨论了其热处理后组织演变与力学性能变化规律的研究进展,旨在探究强约束、快速凝固下高温合金组织调控及力学性能提升方法,进一步拓展激光增材制造技术在航空发动机及燃气轮机等热端结构材料的应用。

     

    Abstract: The thermal stability of the selective laser melted nickel-based superalloys with the complex non-equilibrium solidified microstructure is different from that of the traditional cast and forged counterparts, and the traditional standard heat treatment process cannot obtain the stable structure and excellent properties accordingly. Therefore, it is imperative to clarify the inherent relationship between the metastable precipitate characteristics in non-equilibrium thermal cycles during the additive manufacturing and the heat treatment processes, such as grain growth, second-phase precipitation, and dislocation evolution during the thermal treatment. The γ″ strengthening nickel-based high-temperature alloys (IN718 alloy) were focused in this paper, which were widely used in the fields of aviation engines and gas turbines, the research progress on the microstructure characteristics after laser selective melting forming was discussed, and the microstructure evolution and variation laws of the mechanical properties after heat treatment were reviewed to explore the methods for regulating the microstructure and improving the mechanical properties of high-temperature alloys under the rapid solidification, and to further expand the application of laser additive manufacturing technology in hot-end structural materials, such as aviation engines and gas turbines.

     

/

返回文章
返回