The Effect of Misch Metal on the Microstructure of Rapidly solidified Ag-Sn-In Alloys

급속응고한 Ag-Sn-In 합금의 미세조직에 미치는 Misch Metal의 영향

  • 장대정 (한양대학교 금속재료공학과) ;
  • 남태운 (한양대학교 금속재료공학과)
  • Published : 2007.06.01


Because of a good wear resistance and a stable contact resistance, Ag-CdO is widely used as electrical contact material. But, the Cd-oxide mainly exists as a coarse particle and adversely affected to environment. As a reason, $Ag-SnO_2$ alloy has been developed. The Sn-oxide maintains stable and fine particle even at high temperature. In order to investigate the effect of Misch metal (Mm) additional that affects the formation of the oxide and the formation of fine matrix Ag, we studied the microstructures and properties of Ag-Sn-In(-Mm) material fabricated by rapid solidification process. The experimental procedure were melting using high frequency induction, melt spinning, and internal oxidation. The Mm addition makes Ag matrix more fine than no Mm addition. The reason is that the addition of Misch metal decreased a latent heat of fusion of alloy, as a result the rapid solidification effect of alloy is increased. The maximum hardness shows at 0.3 wt%Mm. after that the hardness is decreased until 0.4 wt% Mm, but still larger than no Mm addition alloy. At 0.5 wt% Mm alloy, the precipitation of Misch metal causes a decrease of hardness than no Mm addition alloy.


  1. D. N. Lee, 'The internal oxidation of Ag-Cd alloys', J Korean Ins. Met., Vol. 14, No.1, p. 20, 1976
  2. G. Bohm and M. Kahlweit, 'On internal oxidation of metallic alloys', ACTA Met,. Vol. 12, p. 641, 1964
  3. Y. S. Shen, E. J Zdanuk, and R. H. Krock, 'The effect of additives from gropps IA and IIA on the morphology and properties of silver-cadmium oxide contacts', Met. Trans., Vol. 8, No.1, p. 16, 1972
  4. WEEE, Waste Electrical and Electronic Equipment
  5. RoHS, Restriction of Hazardous Substances
  6. X. M. Liu, S. L. Wu, Paul K. Chu, C. Y. Chung, J. Zheng, and S. L. Li, 'Effects of coating process on the characteristics of Ag $SnO_2$ contact materials', Materials Chemistry and Physics, Vol. 98, No. 2-3, p. 477, 2006
  7. J. W. Lee and H. -C. Lee, 'Effects of tellurium addition on othe internal oxidation of Ag-Sn alloys', Scripta mater., Vol. 42, p. 169, 2000
  8. P. B. Joshia, P. S. Krishnan, R. H. Patel, V. L. Gadgeel, P. ramakrishnan, and V. K. Kaushik, 'Effect of lithium addition on the density and oxide-phase morphology of Ag-ZnO electrical contact materials', Materials Letters, Vol. 33, p. 137, 1997
  9. 장대정, 권기봉, 김영주, 조대형, 남태운, '급속응고한 Ag-Sn→In계 접점재료의 미세조직 에 미치는 Te의 영향' 전기전자재료학회논문지 , 20권, 1호, p. 86, 2007
  10. R. M. Wang, Y. G. Song, and Y. F. Han, 'Effect of rare earth on the microstructures and properties of a low expansion superalloy', Journal of Alloys and Compounds, Vol. 311, Iss. 1, p. 60, 2000
  11. L. Meng and X. L. Zheng, 'Overview of the effects of impurities and rare earth elements in Al-Li alloys', Materials Science and Engineering A, Vol. 237, Iss. 1, p. 109, 1997