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Lee, J.S.

Paper Title Page
WEPCH183 Enhancement of Mechanical Properties of High Chromium Steel by Nitrogen Ion Implantation 2361
 
  • B.S. Kim, S.-Y. Lee
    Hankuk Aviation University, KyungKi-Do
  • K. R. Kim, J.S. Lee
    KAERI, Daejon
  
  This article reports the study of mechanical properties of high chromium steel after N-ion implantation. The samples are implanted with 120keV N-ion at doses ranging from 1x1017ions/square cm to 4x1018ions/square cm. Mechanical properties of implanted samples are compared with those of Cr-plated samples. The compositions of the N-ion implanted layer were measured by Auger electrons spectroscopy(AES). Their mechanical properties as a function of N-ion doses were characterized by nano-indentation, sliding and impact wear tests. The results reveal that the hardness and mechanical properties of ion implanted samples were found to depend strongly on the ion doses. The hardness of the N-ion implanted sample with 2x1018ions/? was measured to be approximately 9 GPa, which is approximately 2.3 times higher than that of un-implanted sample (H=3.8 GPa). Also wear properties of N-ion implanted samples with 2x1018ions/? were largely improved ;compared to the Cr-plated samples, the width of wear track and friction coefficient developed on the N-ion implanted samples are about 60% and 40% smaller, respectively.  
WEPCH184 Mechanical Properties of WC-Co by Nitrogen Ion Implantation: Improvement of Industrial Tools 2364
 
  • Y. Noh, B.Y. Kim, K. R. Kim, J.S. Lee
    KAERI, Daejon
  
  Ion implantation of WC-Co has been widely investigated for the improvement of wear resistance, but rarely for friction behavior. Although friction is closely associated with wear, more factors influence friction than wear, and low wear does not generally lead to low friction w6x. Therefore, we focus our study on the effects of ion implantation on the mechanical properties in WC-Co cermets, with particular interest in tool industry applications.  
WEPCH189 Design of the 20 MeV User Facilities of Proton Engineering Frontier Project 2376
 
  • K. R. Kim, Jae-Keun Kil. Kil, C.-Y. Lee, J.S. Lee, B.-S. Park
    KAERI, Daejon
  
  The user facilities of PEFP (Proton Engineering Frontier Project) was designed. It is composed of two beamlines at the first stage and has possibility of expansion to five beamlines. One is low flux beamline for the technology developments in the fields of biological and space sciences and the other is high flux beamline for the utilization in the fields of nano and material sciences. The flux density is 1E+8~1E+10 protons/cm2-sec and 1E+10~1E+13 protons/cm2-sec each. The available energy range is 5~20MeV and the irradiation area is larger than 10cm in diameter with uniformity more than 90% for both. The specifications of these beamlines mentioned above were decided on the basis of result of user demand survey and operation experience of 45MeV proton beam test beamline installed at the MC-50 cyclotron of KIRAMS (Korea Institute of Radiological and Medical Science). The key components of these beamlines are bending magnets, magnetic quadrupole doublet or triplet, collimators, scanning magnets, target stage with water cooling system, degrader for energy control, scattering foils for flux control, etc. The beam optics was calculated using TRANSPORT and TRACE 3D simulation code.  
WEPCH191 The Design and Manufacture of a 300 keV Heavy Ion Implanter for Surface Modification of Materials 2382
 
  • J.S. Lee, Jae-Keun Kil. Kil, C.-Y. Lee
    KAERI, Daejon
  
  A 300keV ion implanter has been designed for studies of surface modification of several materials by ion beam. The purpose of design is domestic development of the basic technology for the high energy ion implanter. The main point of design is production, acceleration and transportation of high nitrogen ion beam current up to 5mA and ion energy up to 300keV. 300keV ion implanter consists of Duo-PIGatron ion source, einzel lens, mass separation magnet, acceleration tube, magnetic quadrupole doublet, electrostatic scanner and target. Beam optics design carried out where space charge effect in the acceleration tube and second order aberrations in the mass separation magnet were considered. The mass numbers range from 1 to 140 and the resolving power M/ΔM is 131. Implanter control system includes fiber optics links for the monitoring and control of the ion source parameters in the high voltage zone and computer system for the characterization of the ion beam and whole control of an implantation process.