Field Evaluation of Six Protective Coatings Applied to T56 Turbines after 1500 Hours Engine Use

Abstract

The evaluation of several protective coatings that have been applied to IN738-LC first stage turbine blades in two military gas turbines for an interval of 500 flight hours indicated variations in the extent of hot-corrosion resistance. The coatings included two conventional nickel aluminides, an aluminide modified with chromium, a platinum modified aluminide, an aluminide modified with silicon and a platinum/rhodium modified aluminide. The aim of this trial is to find a coating that will withstand up to 3000 engine operating hours. Detailed metallographic examinations as well as scanning electron microscopy were employed in the evaluation. Results indicated that the precious metal aluminides offered the best protection with the chromium-aluminide being the most susceptible to hot-corrosion. The conflicting results of the basic aluminide coatings reaffirms the point that no firm conclusions can be made solely on one assessment. Furthermore, there was no apparent cracking in any of the coatings.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1991
Accession Number
ADA242824

Entities

People

  • S. G. Russo

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Coatings
  • Corrosion Resistance
  • Electron Microscopy
  • Engineering
  • Gas Turbines
  • Heat Resistant Alloys
  • High Temperature
  • Leading Edges
  • Materials
  • Microscopy
  • Nickel Aluminide
  • Protective Coatings
  • Resistance
  • Scanning Electron Microscopy
  • Systems Engineering
  • Trailing Edges
  • Turbine Blades

Fields of Study

  • Materials science

Readers

  • Aerospace Engineering
  • Computational Modeling and Simulation
  • Surface Engineering/Surface Coating Technology.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene