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Soviet Powder Metallurgy and Metal Ceramics

, Volume 24, Issue 2, pp 111–115 | Cite as

Character of electrical resistivity variation in the sintering of ultrafine powders

  • R. A. Andrievskii
  • S. É. Zeer
  • V. Ya. Ganelin
  • V. N. Lapovok
  • L. I. Trusov
  • S. P. Shumanova
Theory and Technology of Sintering, Thermal, and Chemicothermal Treatment Processes

Conclusions

As a result of oxidation of compacts from nickel and copper UFPs, their electrical resistivities may vary within a wide range. During the vacuum sintering of nickel and copper UFPs changes in electrical resistivity are recorded before densification. During heating the electrical resistivity of compacts may fall at a rate of up to half an order a minute. Measurements of γ and δL/L during repeated heating-and-cooling cycles reveal increases in the electrical resistivity and elongation of specimens, which may be linked with elastic after-effect phenomena. A small rise in electrical resistivity during heating to 100‡C may also be brought about by elastic stress relaxation. An increase in electrical resistivity accompanied by shrinkage during a rise in temperature after isothermal sintering is indicative of rupture of contacts during densification; the extent of this process, which may be linked with sliding of whole particles relative to one another, diminishes with rise in temperature.

Keywords

Oxidation Copper Nickel Shrinkage Electrical Resistivity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Literature cited

  1. 1.
    V. I. Novikov et al., "Character of mass transport processes in the sintering of ultrafine powders," Poroshk. Metall., No. 7, 39–46 (1983).Google Scholar
  2. 2.
    Ya. E. Geguzin, N. A. Makarovskii, and V. V. Bogdanov, "Characteristics of the sintering mechanism of compacts from ultrafine powders," Poroshk. Metall., No. 6, 39–44 (1984).Google Scholar
  3. 3.
    V. N. Lapovok et al., "Formation of nonequilibrium vacancies during the recrystallization of an ultrafine nickel powder," Fiz. Tverd. Tela,25, No. 6, 1846 (1983).Google Scholar

Copyright information

© Plenum Publishing Corporation 1985

Authors and Affiliations

  • R. A. Andrievskii
    • 1
  • S. É. Zeer
    • 1
  • V. Ya. Ganelin
    • 1
  • V. N. Lapovok
    • 1
  • L. I. Trusov
    • 1
  • S. P. Shumanova
    • 1
  1. 1.Moscow Institute of Fine Chemical TechnologyUSSR

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