Surface Fatigue Lives of Case-Carburized Gears With an Improved Surface Finish

Abstract

Previous research provides qualitative evidence that an improved surface finish can increase the surface fatigue lives of gears. To quantify the influence of surface roughness on life, a set of AISI 9310 steel gears was provided with a near-mirror finish by superfinishing. The effects of the superfinishing on the quality of the gear tooth surfaces were determined using data from metrology, profilometry, and interferometric microscope inspections. The superfinishing reduced the roughness average by about a factor of 5. The superfinished gears were subjected to surface fatigue testing at 1.71-GPa (248-ksi) Hertz contact stress, and the data were compared with the NASA Glenn gear fatigue data base. The lives of gears with superfinished teeth were about four times greater compared with the lives of gears with ground teeth but with otherwise similar quality.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2000
Accession Number
ADA378035

Entities

People

  • H. P. Evans
  • M. P. Alanou
  • R. W. Snidle
  • T. L. Krantz

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Computer Programs
  • Databases
  • Fatigue Tests (Mechanics)
  • Finishes
  • Gear Teeth
  • Inspection
  • Lubricants
  • Materials
  • Measurement
  • Mechanical Engineering
  • Metrology
  • Microscopes
  • Military Research
  • Roughness
  • Space Sciences
  • Surface Properties
  • Surface Roughness

Fields of Study

  • Physics

Readers

  • Structural Health Monitoring of Composite Structures.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).