CRACK PROPAGATION IN AIR AND IN VACUUM FOR NICKEL AND A NICKEL -CHROMIUM-ALUMINUM ALLOY

Abstract

Creep rates have been measured for nickel at 1200 F in air and in vacuum and related to the depth of surface cracks in the specimens tested in the 2 environments. The surface cracks were observed to grow faster in air than in vacuum in both short-time and long-time tests. Crack depths, however, could be correlated with creep rates only in the short-time tests. Although no cracks were observed in a relatively brittle Ni-Cr-Al alloy creep tested at 1300 F, the appearance of alloy specimens fractured after interruption in creep indicated that there was a decrease of intergranular cohesion resulting from the diffusion of atmospheric gases into grain boundaries. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 20, 1961
Accession Number
AD0268724

Entities

People

  • M.r. Achter
  • R.j. Sherman

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Alloys
  • Aluminum
  • Aluminum Alloys
  • Boundaries
  • Chromium
  • Cohesion
  • Crack Propagation
  • Cracks
  • Diffusion
  • Environment
  • Grain Boundaries

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Powder metallurgy of Titanium alloys.
  • Structural Health Monitoring of Composite Structures.