摘要
Undercooling solidification under a magnetic field(UMF)is an effective way to tailor the microstructure and properties of Co-based alloys.In this study,by attributing to the UMF treatment,the strength−ductility trade-off dilemma in GH605 superalloy is successfully overcome.The UMF treatment can effectively refine the grains and increase the solid solubility,leading to the high yield strength.The main deformation mechanism in the as-forged alloy is dislocation slipping.By contrast,multiple deformation mechanisms,including stacking faults,twining,dislocation slipping,and their strong interactions are activated in the UMF-treated sample during compression deformation,which enhances the strength and ductility simultaneously.In addition,the precipitation of hard Laves phases along the grain boundaries can be obtained after UMF treatment,hindering crack propagation during compression deformation.
磁场下的过冷处理(UMF)是一类有效调控钴基合金微观结构和性能的方法。通过UMF处理同时提升GH605钴基高温合金的强度和塑性。结果表明,在UMF处理后,合金的晶粒显著细化,基体相固溶度增加,且合金的屈服强度提升。在原始锻态合金中,位错滑移为主要的变形机制;经过UMF处理后,多种变形机制如层错、孪生、位错滑移及其交互作用在压缩变形过程中被激活,导致合金的强度和塑性同时提高。此外,经UMF处理后,可获得沿晶界析出的硬质Laves相,该硬质相可有效阻碍压缩变形过程中裂纹的扩展。
基金
the fund of National Key Laboratory for Precision Hot Processing of Metals,China(No.6142909200104)
State Key Laboratory of Solidification Processing(NPU),China(No.2022-TS-08)
National Training Program of Innovation and Entrepreneurship for Undergraduates.We thank Dr.ZHENG from ZKKF(Beijing)Science&Technology Company for supporting the characterization of the materials.
