An Investigation of the System: Wolfram - Colbalt - Carbon

Abstract

The phases and phase equilibria in the system wolfram-cobalt-carbon have been studied by x-ray diffraction methods, metallographic technique and thermal analysis. An x-ray method is introduced for evaluating compositions and amounts of phases. Diwolfram carbide is shown to possess a defect lattice with 8-21 percent of unoccupied carbon sites. Monowolfram carbide indicates a very narrow range of homogeneity. In addition to the carbide Co(sub 3)WaC, reported previously the existence of double carbides Co(sub 3)W(sub 6)C(sub 2) and Co(sub 3)W(sub 10)C(sub 4) is revealed. Isomorphous carbides are shown to form in corresponding iron and nickel systems. The lattices are solved and the constants measured. The carbide Co(sub 3)W(sub 3)C is shown to be stable, whereas monowolfram carbide is found to be metastable in alloys where wolfram-cobalt ratio is less than one. Tentative diagrams of stable and metastable equilibrium in the system wolfram-cobalt-carbon are proposed. The basic reactions in sintering of cobalt cemented wolfram carbides are explained.

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Document Details

Document Type
Technical Report
Publication Date
May 11, 1951
Accession Number
ADA551467

Entities

People

  • Pekka Rautala

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • C4I

DTIC Thesaurus Topics

  • Chemical Analysis
  • Diffraction
  • Equations
  • Heating
  • High Temperature
  • Materials
  • Measurement
  • Metallurgy
  • Particle Size
  • Particles
  • Phase Transformations
  • Physical Metallurgy
  • Scattering
  • Thermal Analysis
  • Transitions
  • X Rays
  • X-Ray Diffraction

Readers

  • Linear Algebra
  • Materials Science and Engineering.
  • Surface Engineering/Surface Coating Technology.