Phase Analysis of Immiscible V-Cu MA Powders by Neutron and X-ray Diffraction

비고용 V-Cu계 MA합금의 중성자 및 X선 회절에 의한 상분석

  • Published : 2004.05.01


The mechanical alloying (MA) effect in immiscible V-Cu system with positive heat of mixing was studied by not only the neutron and X-ray diffraction but also the analysis of DSC spectra. The total energy, ΔHt accumulated during MA for the mixture of $V_{50}$ $Cu_{50}$ / powders increased with milling time and approached the saturation value of 14 kJ/mol after 120 h of milling. It can be seen that the free energy difference between the amorphous phase and the pure V and Cu powders with an atomic ratio 5:5 is estimated to be 11 kJ/mol by Miedema et al. This is thermodynamically taken as one of the evidences for the amorphization. The structural changes of V-Cu MA powders were characterized by the X-ray diffraction and neutron diffraction. We take a full advantage of a negligibly small scattering length of the V atom in the neutron diffraction measurement. The neutron diffraction data definitely indicate that the amorphization proceeds gradually but incompletely even after 120 h of MA and bcc-Cu Bragg peaks appears after 60 h of MA.


mechanical alloying;neutron diffraction;X-ray diffraction;amorphization;immiscible V-Cu system


  1. J. S. Benjamin, Met. Trans., 1, 2943 (1970)
  2. R. B. Schwarz and C.C. Koch, Appl. Phys. Lett., 49, 146 (1986)
  3. L. Schultz, J. Less-Common Metals, 145, 233 (1988)
  4. J. M. D. Coey and H. Sun, J. Magn. Magn. Mater., 87, L251 (1990)
  5. C. C. Koch, O. B Cavin, C. G. McKamey and J. O. Scarbrough, Appl. Phys. Lett., 43, 1017 (1983)
  6. R. B. Schwarz, R. R. Petich and C. K. Saw, J. Non-Cryst. Solid, 76, 281 (1985)
  7. L. Schultz, J. Less-Common Metals, 145, 233 (1988)
  8. U. Mizutani and C. H. Lee, J. Mat. Sci., 25, 399 (1990)
  9. K. Uenishi, K. F. Kobayashi, K. N. Ishihara and P. H. Shingu, Mater. Sci. & Eng., A, 134, 1342 (1991)
  10. J. Kuyama, H. Inui, S. Imaoka, S. Nasu, K. N. Ishihara and P. H. Shingu, Jpn. J. Appl. Phys., 26, L854 (1991)
  11. Y. Ogino and R. Sakai, J. Non-Cryst. Solids, 117/118, 737 (1990)
  12. J. C. Kim, B. H. Koh, S. T. Oh and I. H. Moon, J. of Korea Powder Metallurgy Institute, 3, 33 (1996)
  13. C. H. Lee, M. Mori and U. Mizutani, J. Non-Crys. Solids, 117-118, 733 (1990)
  14. T. B. Massalski, Binary Alloy Phase Diagrams, 2nd ed., ASM, (1990)
  15. F. R. de Boer, R. Boom, W. C. M. Mattens, A. R. Miedema and A. K. Niessen, Cohesion in Metals, p.265, North-Holland, Amsterdam, (1988)
  16. T. E. Faber and J. M. Ziman, Phil. Magn., 11, 153 (1965)
  17. T. Fukunaga, Y. Homma and K. Suzuki, Mat. Sci. and Eng., A, 134, 987 (1991)
  18. J. L. Finney and J. Wallace, J. Non-Cryst. Solids, 3, 165 (1981)