We first report a fabrication technique of nanoscale speckle patterns on polymers using broad ion beam milling. The proposed technique is simple and low-cost to produce speckles ranging from dozens of nanometers to le...We first report a fabrication technique of nanoscale speckle patterns on polymers using broad ion beam milling. The proposed technique is simple and low-cost to produce speckles ranging from dozens of nanometers to less than three micrometers in a large area of several millimeters. Random patterns were successfully produced with an argon （Ar） ion beam on the surfaces of four kinds of polymers： the epoxy matrix of carbon fiber reinforced plastic, polyester, polyvinyl formal-acetal, and polyimide. The speckle morphologies slightly vary with different polymers. The fabricated speckle patterns have good time stability and are promising to be used to measure the nanoscale deformations of polymers using the digital image correlation method.展开更多
A spherical mask for the fabrication of microlens arrays was prepared by melting photoresist, and the spherical photoresist shape was transferred into a silicon substrate using ion beam milling. The ion beam milling p...A spherical mask for the fabrication of microlens arrays was prepared by melting photoresist, and the spherical photoresist shape was transferred into a silicon substrate using ion beam milling. The ion beam milling process was computer simulated using the Sigmund ion beam sputtering theory of collision cascades. The experiment results show that microlens arrays can be effectively formed at low substrate temperature of less than 200 ℃.Shapes and dimensions of photoresist masks and silicon microlens arrays were examined by the scanning electron microscope and tested by the surface stylus measurement.展开更多
The microstructural evolutions of 5Mn steel during various heat treatments have been investiga- ted by in-situ transmission electron microscopy （TEM）. The specimen of 5Mn steel was pre- pared using focused ion beam ...The microstructural evolutions of 5Mn steel during various heat treatments have been investiga- ted by in-situ transmission electron microscopy （TEM）. The specimen of 5Mn steel was pre- pared using focused ion beam （FIB） milling, which allowed the selection of specific morphology of interest prior to the in-situ observation, The complete austenization at 800 ℃ was verified at the atomic scale by minimizing thermal expansion and sample drift in a heating holder based on micro-electro-mechanical-systems. During annealing at 650 ℃, the formation of reverted austen- ite was dynamically observed, while the morphologies of austenite laths of 5Mn steel after in-situ heating were quite similar to that after ex-situ intereritical annealing. During annealing at 500 ℃, the morphological evolution of cementite and associated Mn diffusion were investigated. It was demonstrated that a combination of FIB sampling and high temperature in-situ TEM enables us to probe the morphological evolution and elemental diffusion of specific areas of interest in steel at high spatial resolution.展开更多
基金supported by Cross-ministerial Strategic Innovation Promotion Program (Unit D66) Innovative MeasurementAnalysis for Structural Materials (SIP-IMASM) operated by the Cabinet Office, Japan
文摘We first report a fabrication technique of nanoscale speckle patterns on polymers using broad ion beam milling. The proposed technique is simple and low-cost to produce speckles ranging from dozens of nanometers to less than three micrometers in a large area of several millimeters. Random patterns were successfully produced with an argon （Ar） ion beam on the surfaces of four kinds of polymers： the epoxy matrix of carbon fiber reinforced plastic, polyester, polyvinyl formal-acetal, and polyimide. The speckle morphologies slightly vary with different polymers. The fabricated speckle patterns have good time stability and are promising to be used to measure the nanoscale deformations of polymers using the digital image correlation method.
文摘A spherical mask for the fabrication of microlens arrays was prepared by melting photoresist, and the spherical photoresist shape was transferred into a silicon substrate using ion beam milling. The ion beam milling process was computer simulated using the Sigmund ion beam sputtering theory of collision cascades. The experiment results show that microlens arrays can be effectively formed at low substrate temperature of less than 200 ℃.Shapes and dimensions of photoresist masks and silicon microlens arrays were examined by the scanning electron microscope and tested by the surface stylus measurement.
基金funded by National Basic Research Program of China(2010CB630800,2015CB921700)National Natural Science Foundation of China(51671112,51471096,51390471,11374174)+2 种基金National Key Research and Development Program(2016YFB0700402)National Key Scientific Instruments and Equipment Development Project(2013YQ120353)Tsinghua University(20141081200)
文摘The microstructural evolutions of 5Mn steel during various heat treatments have been investiga- ted by in-situ transmission electron microscopy （TEM）. The specimen of 5Mn steel was pre- pared using focused ion beam （FIB） milling, which allowed the selection of specific morphology of interest prior to the in-situ observation, The complete austenization at 800 ℃ was verified at the atomic scale by minimizing thermal expansion and sample drift in a heating holder based on micro-electro-mechanical-systems. During annealing at 650 ℃, the formation of reverted austen- ite was dynamically observed, while the morphologies of austenite laths of 5Mn steel after in-situ heating were quite similar to that after ex-situ intereritical annealing. During annealing at 500 ℃, the morphological evolution of cementite and associated Mn diffusion were investigated. It was demonstrated that a combination of FIB sampling and high temperature in-situ TEM enables us to probe the morphological evolution and elemental diffusion of specific areas of interest in steel at high spatial resolution.
