@article{oai:kitami-it.repo.nii.ac.jp:00006980,
 author = {YAN, Jiwang and TAKAHASHI, Yasunori and TAMAKI, Jun-ichi and KUBO, Akihiro and KURIYAGAWA, Tsunemoto and SATO, Yutaka},
 issue = {1},
 journal = {JSME International Journal Series C},
 month = {Jan},
 note = {Germanium is an excellent infrared optical material. 0n most occasions, singlecrystalline germanium is used as optical lens substrate because its homogeneous structure is beneficial for fabricating uniform optical surfaces.　In this work, we attempt to use poly crystals as lens substrates instead of single crystals, which may lead to a significant reduction in production cost. We conducted ultraprecision cutting experiments on poly-crystanine germanium to examine the microscopic machinability. The crystal orientations of specific crystal grains were characterized, and the machining characteristics of these crystal grains including surface textures, cutting forces, and grain boundary steps were investigated under various machining conditions. It was possible to produce uniformly ductile-cut surfaces cross all crystal grains by using an extremely small undeformed chip thickness (～80nm)under negative tool rake angles (～－45°).This work indicates the possibility of fabricating high-quality infrared optical components from poly-crystalline germanium.},
 pages = {63--69},
 title = {Ulitaprecision Machining Characteristics of Poly-Crystalline Germanium},
 volume = {49},
 year = {2006}
}