基体取向对激光熔覆修复区域杂晶形成的影响  

Effect of Substrate Orientation on Formation of Heterocrystals in Laser Cladding Zone

作　　者：荣鹏 郭嘉琛 Rong Peng;Guo Jiachen(Chengdu Aircraft Industrial(Group)Co.,Ltd,Chengdu,Sichuan 610000,China;School of Science,Northwestern Polytechnical University,Xi'an,Shanxi 710072,China)

机构地区：[1]成都飞机工业(集团)有限责任公司,四川成都610000 [2]西北工业大学理学院,陕西西安710072

出　　处：《中国激光》2021年第6期127-136,共10页Chinese Journal of Lasers

摘　　要：镍基单晶高温合金叶片的表面缺陷修复是实现其制造及延寿技术的关键,也是材料物理与化学学科的热点研究问题。提出了一种激光熔凝二次旋转基体修复单晶合金的新方法,采用实验与理论模型相结合的方式,以DD6镍基高温合金为研究对象,探究了绕[010]方向旋转45°、再沿[001]方向旋转不同角度ξ时不同晶向区域的分布变化规律。实验结果表明,随着ξ的增大,熔池内一侧单一晶向区域分布增大,同时获得了可使熔池一侧只存在单一晶区的基体取向(11√2)[√201](即ξ=45°)。本研究揭示了激光熔凝单晶高温合金过程中改变基体晶向对外延生长组织内部杂晶形成能力的影响机制,并为修复单晶高温合金叶片表面缺陷的激光熔覆修复技术提供了全新的优化思路。Objective Renovating surface defects of Ni-based single crystal superalloy blades is the key to prolong their manufacturing life,and repair mechanism is also a hot research topic in material physics and chemistry.In this study,laser melting method combined with theoretical model calculation is used,and the self-developed DD series Ni-based superalloys in China is taken as the research object.On the basis of previous studies,the substrate orientation has rotated 45°around the direction of[010]during laser melting of single crystal alloys,then rotate different anglesξalong the direction of[001],the distribution and variation of different crystal orientation regions with the increase ofξare studied.It is found that with the increase ofξ,the distribution of single crystal domain increases on the side of molten pool.Substrate orientation(11√2)[√201]]with single crystal region on one side of molten pool is obtained.Repairing operation on its substrate,because of the disappearance of[010]domain in the molten pool of epitaxial growth repair zone,the grain boundary[001]/[010]also disappears,the ability of stray grain formation is greatly reduced.The substrate orientation suitable for laser cladding repair is obtained,and the mechanism of the effect of changing substrate orientation on the formation ability of stray grain in the epitaxial growth structure is demonstrated.Methods In our previous research,the mechanism of substrate orientation for the formation of equiaxed crystals has been elaborated in detail.It is defined that when the laser scans along the[100]direction on the crystal plane,that is,the substrate orientation relationship is the initial substrate orientation.When the initial matrix is rotated 45°around the crystal direction(i.e.,the y-axis),the growth of heterocrysts can be effectively suppressed.On this basis,this study continues to take the crystal direction as the rotation axis.Through the second rotation of differentξand laser melting technology,the mechanism of inhibiting the growth of heter

关 键 词：激光技术 单晶高温合金叶片 激光熔覆修复技术 基体取向 敏感度 

分 类 号：TN249[电子电信—物理电子学] TG113[金属学及工艺—物理冶金]