The Effect of Microstructure on the Fatigue Crack Growth Resistance of Nickel Base Superalloys.

Abstract

The objective of this study is to determine the effect of microstructural properties on the fatigue crack propagation (FCP) response of nickel base superalloys. This report describes the results of four experimental alloys containing various amounts of aluminum, titanium, and molybdenum. Chemistry, precipitate size, and grain size were varied to produce systematically controlled microstructures. The four alloys were characterized for chemical composition, microstructure, tensile properties, low cycle fatigue (LCF), and FCP resistance. The FCP tests were performed under constant load (increasing K) conditions in air at a stress ratio (R) of 0.1 and 0.8. Closure loads were measured with a clip gage, back-face strain gage, and a laser extensometer. Keywords: Fatigue crack propagation, Nickel base superalloys, Microstructure, Closure, Mismatch, Anti phase boundary.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1987
Accession Number
ADA189526

Entities

People

  • Stephen D. Antolovich

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Chemistry
  • Electron Microscopes
  • Grain Size
  • Materials
  • Materials Engineering
  • Materials Science
  • Measurement
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Metallurgy
  • Modulus Of Elasticity
  • Particle Size
  • Particles
  • Plastic Properties
  • Shear Modulus
  • Stress Strain Relations

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Powder metallurgy of Titanium alloys.

Technology Areas

  • Directed Energy