GH4169合金磨削表面塑性变形层的微观结构

发布时间：2018-03-20 06:35

本文选题：GH合金　切入点：磨削表面　出处：《机械工程学报》2015年12期 　论文类型：期刊论文

【摘要】：采用光学显微镜、透射电子显微镜和高分辨透射电子显微镜对航空发动机常用高温合金GH4169磨削表面变质层的微观组织结构进行研究。结果表明,GH4169合金磨削表面及亚表面发生了局部剧烈塑性变形,在表面变质层内形成了剧烈塑性变形层(Severe plastic deformation layer,SPDL)。通过分析选区电子衍射图特征,确定出本试验条件下磨削表面塑性变形层的深度略大于2.2μm。根据组织特点,磨削表面的SPDL进一步可分为表面非晶层、微观剪切带和纳米晶层。表面非晶层最靠近外表面,其内主要为非晶组织和高密度的空位,但仍存在一定量的直径为1~3 nm的有序结构。微型剪切带是位于表面非晶层和纳米晶层之间、平行于磨削表面、宽度约2 nm的一条带状区域,其内组织已经完全非晶化,不存在有序结构。纳米晶层紧邻基体,主要是直径为10~150 nm的纳米晶粒,纳米晶粒内部原子排列基本有序,但仍存在大量的晶格缺陷,主要为非晶化、位错、层错和孪晶。
[Abstract]:Using an optical microscope, Transmission electron microscopy (TEM) and high resolution transmission electron microscope (HRTEM) were used to study the microstructure of the surface modification layer of GH4169 superalloy, which is commonly used in aero-engine grinding. The results show that the grinding surface and subsurface of HGH4169 alloy have local severe plastic deformation. A severe plastic deformation layer, Severe plastic deformation layer, is formed in the surface metamorphic layer. By analyzing the characteristics of selected area electron diffraction patterns, it is determined that the depth of the grinding surface plastic deformation layer is slightly greater than 2.2 渭 m under the experimental conditions. The SPDL of grinding surface can be further divided into surface amorphous layer, micro shear band and nanocrystalline layer. The surface amorphous layer is closest to the outer surface, which is mainly composed of amorphous structure and high density vacancy. However, there is still a certain amount of ordered structure with a diameter of 1 ~ 3 nm. The micro shear band is a strip region between the amorphous layer and nanocrystalline layer on the surface, parallel to the grinding surface, with a width of about 2 nm, and its inner structure has been completely amorphous. There is no ordered structure. The nanocrystalline layer is mainly nanocrystalline with a diameter of 10 ~ 150nm. The atoms in the nanocrystalline are arranged orderly, but there are still a lot of lattice defects, such as amorphous, dislocation, stacking fault and twin.
【作者单位】：西北工业大学现代设计与集成制造技术教育部重点实验室;西安应用光学研究所;
【基金】：国家自然科学基金资助项目(51175430)
【分类号】：TG580.6

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