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Journal of Materials Science

, Volume 27, Issue 23, pp 6417–6425 | Cite as

Removal of surface carbides from spark-machined molybdenum and tungsten

  • K. P. Cooper
  • J. D. Ayers
  • C. L. Vold
Papers

Abstract

When reactive metals such as molybdenum and tungsten are shaped by electrical discharge machining in the kerosene-based electrolytes generally employed for the process, they become covered with a thin, multiply-melted surface layer which contains carbide phases of variable composition. This surface layer is sometimes undesirable because its chemical and mechanical properties are different from the base metals. It has been demonstrated that the carbide can be removed by a high-temperature anneal in a reducing atmosphere. The anneal also removes surface cracks on molybdenum introduced by the machining, but the heat treatments employed here did not remove surface cracks on tungsten. The high-temperature anneal had the unfortunate side effect of inducing a significant degree of grain coarsening in the metals.

Keywords

Polymer Atmosphere Mechanical Property Carbide Heat Treatment 
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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Copyright information

© Chapman & Hall 1992

Authors and Affiliations

  • K. P. Cooper
    • 1
  • J. D. Ayers
    • 1
  • C. L. Vold
    • 1
  1. 1.Physical Metallurgy BranchNaval Research LaboratoryWashington, DCUSA

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