Ứng dụng của vật liệu từ mềm Vô định hình


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  • Ứng dụng của vật liệu từ mềm Vô định hình

    1. 1. Application of soft magnetic of amorphous alloys Nguyen Hoang Viet Nano-Particulate Materials Processing (NPMP)
    2. 2. Contents <ul><li>Introduction </li></ul><ul><li>Amorphous structure characterizations </li></ul><ul><li>Application </li></ul><ul><ul><li>Alloys </li></ul></ul><ul><ul><li>Preparation </li></ul></ul><ul><ul><li>Device </li></ul></ul><ul><li>Summaries </li></ul>
    3. 3. Amorphous configuration exhibits unique properties such as h igh strength, large elastic limit, excellent wear & corrosion resistance… Terms: Amorphous Alloys, (Bulk) Metallic glasses, Inorganic Amorphous Materials,… Crystalline Structure Amorphous Structure Properties of Metallic Glasses High strength & elasticity of BMGs Potential for structural application High strength of Ti- based BMGs ~ 2200MPa Adapted from http:// www.nanonet.go.jp/english/mailmag/2004/014a.html Characteristics of Metallic Glass
    4. 4. Diffraction pattern (TEM) Complete amorphization after 20h of MA Ti 50 Cu 25 Ni 20 Sn 5 amorphous alloy by MA Amorphous Structure Charactezations DSC analysis Glass transition Temp. Crystallization Temperature After Oanh NH et. al. NPMP LAB [3] .
    5. 5. Alloys [5] <ul><li>Class of alloys [2] : containing about 80 atom % of the transition metals Fe, Co, and Ni, and about 20 atom % of metalloid elements sauch as B, C, P, Ge and Si. </li></ul><ul><ul><li>Fe-based alloys: high saturation induction, low permeability and high magnetostriction. >> low frequency app.; big mass; low price </li></ul></ul><ul><ul><li>Fe-Ni-based alloys: medium saturation induction and permeability. >> better high frequency app. </li></ul></ul><ul><ul><li>Co-based alloys: relatively low saturation induction but excellent high-frequency & nearly zero magnetostriction. >> special app. (magnetic head, sensors, etc.), smaller mass, high price </li></ul></ul>Application
    6. 6. Preparation [5] *: rapid quenching method **: sintering – SPS, hot press, hot extrusion,… Mold casting, consolidation of amor. powder and ribbon ** . Bulk Water-in quenching technique * Wire Planar flow (tape) casting * or melt spinning Ribbon Mechanical alloying, atomization * , electrodeposition Powder Method Form
    7. 7. Relationship between permeability,  e (at 1 kHz) and saturation polarization for soft magnetic materials (adapted from Ref. [193] [4] ). Isotropic magnetic properties? Stress – differences in cooling rates through thickness of ribbons => Anisotropy Thermal annealing – removal of internal stresses => Mitigating the Anisotropy Fig.: The Nd 60 Fe 10 Co 20 Al 10 alloys prepared by splat quenching, melt spinning, and mold casting. Primary crystallization of amorphous precursors => very fine nanocrystalline grain size in amorphous matrix
    8. 8. Designing and developing a nanocrystalline soft magnetic material from an amorphous precursor route [5-Michael E. McHenry et. al. ]
    9. 9. Devices <ul><li>Excellent soft magnetic of magnetic glasses applied in various devices belong to these groups [4] : </li></ul><ul><ul><li>Power electrical devices: transformer, Motors </li></ul></ul><ul><ul><li>Inductive components used in electrics </li></ul></ul><ul><ul><li>Magnetic heads </li></ul></ul><ul><ul><li>Magnetic shields </li></ul></ul><ul><ul><li>Sensors & transducers </li></ul></ul>
    10. 10. <ul><li>Magnetic heads </li></ul><ul><ul><li>Co-based amor. materials: nearly zero magnetostriction, high density, high frequency and high reproducibility recording. </li></ul></ul><ul><ul><li>Co-Zr-based thin film in heads for perpendicular magnetic recording. </li></ul></ul>
    11. 11. <ul><li>Sensors [4] : </li></ul><ul><ul><li>Magnetometers: using zero-magnetostrictive alloys. Co-base amor. alloy </li></ul></ul><ul><ul><li>Stress sensors: using high magnetostrictive alloys. Fe-base amor. alloy </li></ul></ul>
    12. 14. Summaries <ul><li>The progress in amor. magnetic materials is characterized by the further improvement of the materials and devices rather than by the appearance of new alloys and new fields of application. Several devices are commercially available, e.g., magnetic heads and shields, inductive components for the electronics industry, ribbons for anti-thief security systems, etc. </li></ul><ul><li>Some types of sensors have already found practical use . </li></ul><ul><li>With regard to amorphous cores in distribution and power transformers their usage is strongly influenced not only by the need to solve a number of technical problems but also by the improvement of traditional materials. </li></ul><ul><li>The application of metallic glasses has not proceeded as quickly as was thought earlier and as was to be expected in view of the saving in energy. </li></ul>
    13. 15. References <ul><li>“ MAGNETIC PROPERTIES OF AMORPHOUS ALLOYS”, C. D. Graham, Jr. and T. Egami, Ann. Rev. Mater, Sci. 1978. 8:423-57 </li></ul><ul><li>“ Metallic Glasses”, Gary J. Shiflet, Ullmann's Encyclopedia of Industrial Chemistry, Copyright © 2007 by John Wiley & Sons, Inc. </li></ul><ul><li>Ph.D thesis, Oanh NH, 2006 </li></ul><ul><li>“ Amorphous and nanocrystalline materials for applications as soft magnets”, Michael E. McHenry*, Matthew A. Willard, David E. Laughlin, Progress in Materials Science 44 (1999) 291-433 </li></ul><ul><li>Recent progress in the Application of Soft Magnetic Amorphous materials: Alloys, Preparation, Devices, G. Konczos et la., Physica Scripta, Vol. 124, 42-48, 1988 </li></ul>
    14. 16. Many Thanks for your attention!