Failure Analysis of a Pitch Link Self-Locking Nut MS 17825-10

Abstract

The Aviation and Troop Command (ATCOM) shipped a broken self-locking nut to the Army Research Laboratory-Materials Directorate (ARL-MD) and requested a metallurgical investigation to determine the probable cause of failure. The component was received on 31 October 95, hexagon shaped, castellated self-locking nut, MS 17825-10, was attached to the lower end of the pitch link located on an army attack helicopter. The outside of the nut contained the manufacturer's designation which consisted of the letter 'G' stamped 5 times along a longitudinal section of the part. The nut was fabricated from non-corrosion resistant steel and is to he used at temperatures up to 250 deg F. During assembly while applying torque, the nut cracked and split open. Further inspection revealed that the nut was cracked at one of the castellations.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1996
Accession Number
ADP010186

Entities

People

  • Scott M. Grendahl

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Attack Helicopters
  • Chemical Analysis
  • Corrosion
  • Cracks
  • Electron Microscopy
  • Emission Spectroscopy
  • Failure Analysis
  • Hardness
  • Inclusions
  • Materials
  • Mechanical Properties
  • Microscopy
  • Military Research
  • Scanning Electron Microscopy
  • Specifications
  • Surface Roughness
  • Tensile Strength

Readers

  • Electrical Engineering
  • Materials Science and Engineering.
  • Structural Health Monitoring of Composite Structures.