FRACTURE OF METALS

Abstract

A study was made of the mechanism of brittle fracture produced in engineering metals under stress when wetted by certain low-melting liquid metals and the relation these phenomena have to similar behavior in other environments. The embrittlement by mercury of Al alloys in various states of anneal, cold work, and aging was studied. Sub-yield point failure is confined to dispersion-hardened structures and is intensified by combinations of aging and small degrees of cold work. Large plastic strains imposed upon the aged state reduce the level of embrittlement. The case is made that a critical strain rather than a critical stress condition governs the occurrence of brittle fracture. A model for the various trends of embrittlement was built from considerations of slip plane population, coherency stress fields, and the interactions between these. The conditions for sub-yield point brittle fracture in quenched and tempered 300M steel as-H-charged or as-wetted with molten Li are the same. The embrittlement by stress-corrosion of Al alloys i being studied to indicate that the embrittlement was basically similar to that produced by wetting with liquid Hg.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1961
Accession Number
AD0268558

Entities

Organizations

  • IIT Research Institute

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Alloys
  • Biaxial Stresses
  • Corrosion
  • Crystal Structure
  • Dispersions
  • Engineering
  • Hydrogen Embrittlement
  • Materials
  • Mechanical Properties
  • Mechanical Working
  • Shear Stresses
  • Solid Solutions
  • Stress Corrosion
  • Stress Corrosion Cracking
  • Tensile Strength
  • Tensile Stress
  • Yield Strength

Readers

  • Materials Science (Mechanical Engineering).
  • Surface Engineering/Surface Coating Technology.