FLOW AND FRACTURE OF MOLYBDENUM UNDER SPACE VACUUMS,

Abstract

A model is postulated that accounts for the low-pressure-dependent ductility effect in bulk polycrystalline molybdenum deformed in tension at ambient temperature; a hydrogen type of embrittlement mechanism is proposed. This model is based on experimental data. The vacuum dependence of specimen ductility is related to the rate of gaseous monolayer coverage and subsequent surface diffusion of mobile atoms onto available atomic sites. This occupation of free atomic sites, in turn, impedes the release (also by diffusion) of contaminant gases from within the material and results in large internal pressures at crack sites at or near the surface. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1968
Accession Number
AD0673349

Entities

People

  • Seymour Feuerstein

Organizations

  • The Aerospace Corporation

Tags

DTIC Thesaurus Topics

  • Diffusion
  • Ductility
  • Embrittlement
  • Environmental Pollutants
  • Experimental Data
  • Hydrogen
  • Internal Pressure
  • Material Degradation Processes
  • Materials
  • Molybdenum
  • Monomolecular Films
  • Polycrystals

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Materials Science and Engineering.
  • Thin Film Deposition Science.

Technology Areas

  • Space