Accession Number:

ADA422266

Title:

Validation of HVOF WC/Co Thermal Spray Coatings as a Replacement for Hard Chrome Plating on Aircraft Landing Gear

Descriptive Note:

Final rept.

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Report Date:

2004-03-31

Pagination or Media Count:

275.0

Abstract:

Hard chromium electroplating is extensively used by aircraft manufacturers and military maintenance depots to provide wear andor corrosion resistance or to restore dimensional tolerance to components. However, chrome plating utilizes hexavalent chromium, which is a highly toxic carcinogen, and increasingly stringent environmental and worker-safety regulations are making chrome plating more expensive for the DoD. This document constitutes the final report on a project to quality high-velocity oxygen-fuel HVOF thermal spray WCCo coatings as a replacement for hard chrome plating on landing gear components. Extensive fatigue, wear, corrosion, impact, and hydrogen embrittlement test results comparing the WCCo coatings against hard chrome are presented. The results of rig and flight-testing of HVOF WCCo coatings on landing gear components are also presented. in general, the performance of the WCCo coatings was superior to hard chrome. Producibility issues such as stripping, grinding, and non-destructive inspection of the coatings were addressed. CostBenefit analyses indicate that military repair depots that overhaul landing gear can realize substantial savings by converting from hard chrome to HVOF. Specifications were developed for the WCCo powder, the coatings deposition parameters, and the grinding of the WCCo coatings.

Subject Categories:

  • Coatings, Colorants and Finishes
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE