烧结钕铁硼一维应力层裂实验研究  

Experimental Study on One Spalling of Sintered NdFeB under One Dimensional Stress Loading

作　　者：郭磊 马东方 黄栩凯 夏肇东 王焕然[1] GUO Lei;MA Dongfang;HUANGg Xukai;XIA Zhaodong;WANG Huanran(Faculty of Mechanical Engineering&Mechanics,Key Laboratory of Impact and Safety Engineering(Ningbo University),Ministry of Education,Ningbo 315211,China;College of Science and Technology Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学机械工程与力学学院宁波大学冲击与安全工程教育部重点实验室,浙江宁波315211 [2]宁波大学科学技术学院,浙江宁波315211

出　　处：《热加工工艺》2021年第20期49-54,共6页Hot Working Technology

基　　金：国家自然科学基金项目(11572164)。

摘　　要：利用分离式Hopkinson压缩试验装置(SHPB)进行烧结钕铁硼(NdFeB)试件的一维应力层裂实验。使用超高速摄影机并结合数字图像相关方法(DIC),获得了试件的变形与层裂过程描述,确定层裂位置及其应变,并用于计算层裂强度。采用激光测速技术,获得试件的自由面速度历史,并用于计算试件的层裂强度。利用SEM观察断口微观形貌,分析烧结钕铁硼的动态断裂机理。结果表明,在冲击速度8.6~24.7 m/s内,试件的层裂强度及层裂次数随冲击速度的增加而增加。由DIC获得的层裂区应变计算的试件层裂强度略高于使用自由面速度回跳计算的结果。Based on split Hopkinson pressure bar(SHPB),the one-dimensional stress spalling tests of sintered NdFeB specimens were carried out.The failure process of the specimen was obtained by using ultra-high speed camera combined with digital image correlation(DIC).The location,localized strain and strength of spalling of the specimens were determined by DIC results.The free surface velocity history of the specimen was measured by laser velocimetry,and the spall strength of the specimen was calculated by free surface velocity pull-back.The dynamic fracture mechanism of sintered NdFeB was analyzed by SEM.The results show that the number and strength of the specimen spalling increase with the increase of impact velocity in the range of 8.6-24.7 m/s.The spall strength of the specimen determined by localized strain given by DIC is slightly higher than that calculated by free surface velocity pull-back.

关 键 词：烧结NDFEB DIC方法 自由面速度历史 层裂强度 断裂机理 

分 类 号：TG115.5[金属学及工艺—物理冶金]