Sm_(2)Co_(17)型永磁材料弹塑变形阶段的微纳压痕尺寸效应  

Micro/Nano Indentation Size Effect of Sm_(2)Co_(17)-Type Permanent Magnet during Elasto-Plastic Deformation

作　　者：王磊[1,2] 李强峰 刘友好 方以坤 衣晓飞[2] 李卫 Wang Lei;Li Qiangfeng;Liu Youhao;Fang Yikun;Yi Xiaofei;Li Wei(Division of Functional Materials Research,Central Iron and Steel Research Institute,Beijing 100081,China;State Key Laboratory of Rare Earth Permanent Magnetic Materials,Hefei 231500,China)

机构地区：[1]钢铁研究总院功能材料研究所 [2]稀土永磁材料国家重点实验室

出　　处：《中国稀土学报》2022年第3期425-430,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51871063,51771055)资助。

摘　　要：采用准静态法分别对固溶态和最终态Sm_(2)Co_(17)型永磁的两种取向面样品进行了纳米压痕分析。结果表明,两类磁体不同取向面上的硬度和弹性模量均出现了随着压入深度的增加而减小的现象,表现出典型的压痕尺寸效应。基于Nix-Gao模型的硬度与压入深度拟合结果表明,两种磁体的硬度H_(0)和特征长度h^(*)均呈现出明显各向异性。较大的h^(*)值揭示出最终态磁体在较大的压入深度范围内可观察到明显的尺寸效应现象。进一步地,通过计算反映压痕尺寸效应强弱的效应因子i可知,最终态磁体的i值均比固溶态磁体的大,其中在取向平行加载方向时,i值高出58%。最终态Sm_(2)Co_(17)磁体中存在的胞状组织结构增强了尺寸效应因子,进而改善了Sm_(2)Co_(17)型磁体在弹塑变形阶段的塑性。Nanoindentation experiments are carried out on surfaces with different orientations cut from Sm_(2)Co_(17)-type permanent magnets in as-solution-treated state and final stage by quasi-static method,respectively.The results showed that the hardness and elastic modulus of the two magnets on different orientations surface decrease with the increase of the loading depth,showing a typical indentation size effect.The fitting results of hardness and loading depth based on the Nix-Gao model show that the hardness H_(0) and characteristic length h^(*) of the two types of magnets have obvious anisotropy.The larger h^(*) value indicates that the indentation size effect can be observed in the larger range of indentation depth of the final magnet.Further,the indentation size effect factor i is calculated.The i values of the samples with different orientations of the final state magnet are all larger than those of the assolution-treated magnet,especially when the orientation is parallel to the loading direction,which is 58%higher.This means that the nanostructure cellular structures in the final Sm_(2)Co_(17)-type magnet enhance the indentation size effect factor,which improves the plasticity of the Sm_(2)Co_(17)-type magnet in the elasto-plastic deformation stage.

关 键 词：钐钴磁体 纳米压痕 尺寸效应 硬度 特征长度 

分 类 号：TM273[一般工业技术—材料科学与工程]