Sustained-Load Cracking of Titanium: A Survey of 6Al-4V Alloys

Abstract

This survey reveals that degradation in load-carrying capacity owing to sustained-load cracking (SLC) is widespread and serious in alloys of the Ti-6Al-4V family. Each of eight different one inch (2.5-cm) thick plates tested in air at room temperature exhibited the effect, with degradations ranging up to 35%. The amount of degradation does not seem to correlate with differences in hydrogen content, processing variables, or strength and toughness levels; however, the susceptibility to SLC is orientation dependent. Invalidity of several of the rising-load fracture toughness values, with respect to plane-strain criteria, makes quantitative comparison of degradations uncertain. However, the threshold stress-intensity factor below which SLC failures will not occur, KIt, clearly represents a more conservative fracture-safe design parameter than the plane-strain fracture toughness KIc, which cannot account for insidious time-delayed failures owing to SLC.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Aug 24, 1973
Accession Number
AD0767307

Entities

People

  • C. A. Griffis
  • George R. Yoder
  • Thomas W. Crooker

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Alloys
  • Corrosion
  • Crack Tips
  • Cracks
  • Ferrium
  • Fracture (Mechanics)
  • Hydrogen
  • Hydrogen Embrittlement
  • Materials
  • Mechanics
  • Payload
  • Resistance
  • Stress Corrosion
  • Stress Corrosion Cracking
  • Stress Intensity Factors
  • Stress Tests
  • Titanium Alloys

Readers

  • Applied Combinatorial Optimization and Logic Circuit Design.
  • Materials Science (Mechanical Engineering).
  • Mathematics or Statistics