本文结合聚焦离子束-电子束(Focused ion beam-electron beam,简称FIB-EB)双束系统和真空镀膜工艺,进行微区散斑的制备工艺研究,并将所发展的微散斑制备工艺应用于喷丸镍基合金材料表面制斑,进而结合切槽法进行残余应力高温释放规律的...本文结合聚焦离子束-电子束(Focused ion beam-electron beam,简称FIB-EB)双束系统和真空镀膜工艺,进行微区散斑的制备工艺研究,并将所发展的微散斑制备工艺应用于喷丸镍基合金材料表面制斑,进而结合切槽法进行残余应力高温释放规律的测量研究。在FIB-EB双束系统下记录切槽前后制斑微区的图像,利用数字图像相关法计算切槽后的位移,结合InglisMuskhelishvili理论公式可计算得到残余应力。文中研究了不同温度及保温时间对残余应力释放的影响规律。结果表明,残余应力随保温时间的增长释放速度逐渐减小,最后残余应力趋于稳定值。同时,温度越高,残余应力释放越彻底,800℃下近乎完全释放。该工艺具有适用性好,效率高等优点,可望在材料微区变形测量中得到进一步应用。展开更多
The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patte...The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patterns are fabricated by directly etching the counterpart of the specimen to the black part of a template.Mean intensity gradient is used to evaluate the quality of these SEM images of speckle patterns fabricated based on different templates to select an optimum template.The pattern size depending on the displacement measurement sensitivity is adjusted by altering the magnification of FIB according to the relation curve of the etching size versus magnification.The influencing factors including etching time and ion beam current are discussed.Rigid body translation tests and rotation tests are carried out under SEM to verify the reliability of the fabricated speckle patterns.The calculated values are in good agreement with the imposed ones.展开更多
文摘本文结合聚焦离子束-电子束(Focused ion beam-electron beam,简称FIB-EB)双束系统和真空镀膜工艺,进行微区散斑的制备工艺研究,并将所发展的微散斑制备工艺应用于喷丸镍基合金材料表面制斑,进而结合切槽法进行残余应力高温释放规律的测量研究。在FIB-EB双束系统下记录切槽前后制斑微区的图像,利用数字图像相关法计算切槽后的位移,结合InglisMuskhelishvili理论公式可计算得到残余应力。文中研究了不同温度及保温时间对残余应力释放的影响规律。结果表明,残余应力随保温时间的增长释放速度逐渐减小,最后残余应力趋于稳定值。同时,温度越高,残余应力释放越彻底,800℃下近乎完全释放。该工艺具有适用性好,效率高等优点,可望在材料微区变形测量中得到进一步应用。
基金supported by the National Basic Research Program of China (Grant Nos.2010CB631005 and 2011CB606105)the National Natural Science Foundation of China (Grant Nos.90916010 and 11172151)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20090002110048)
文摘The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patterns are fabricated by directly etching the counterpart of the specimen to the black part of a template.Mean intensity gradient is used to evaluate the quality of these SEM images of speckle patterns fabricated based on different templates to select an optimum template.The pattern size depending on the displacement measurement sensitivity is adjusted by altering the magnification of FIB according to the relation curve of the etching size versus magnification.The influencing factors including etching time and ion beam current are discussed.Rigid body translation tests and rotation tests are carried out under SEM to verify the reliability of the fabricated speckle patterns.The calculated values are in good agreement with the imposed ones.
