Objective: 

The objective of this project is to demonstrate and validate supersonic particle deposition (SPD) of aluminum (Al) alloy coatings as a cost-effective, environmentally acceptable technology to impart surface protection and restore dimensional tolerances to magnesium alloy components on Department of Defense (DoD) helicopters and fixed-wing aircraft. This includes establishment of a demonstration SPD facility at Naval Air Depot Cherry Point (NADEP-CP), development and execution of a materials joint test protocol that would include field testing, and application of coatings to actual components for lead-the-fleet flight testing.

Technology Description: 

The SPD process involves introduction of a powder and moderately heated inert gas into a gun onto which is attached a nozzle from which the gas and powder mix exits at supersonic velocities. The powder impacts onto a surface, rapidly depositing a coating with very high density, uniform microstructure, and low residual stresses. The Army Research Laboratory (ARL) has established an SPD facility and demonstrated several applications for the technology on DoD weapons systems. Due to the potential localized nature of the deposition, the low temperatures involved, and the properties of the deposited Al alloys, SPD is considered a clear choice over alternative thermal spray or other coatings technologies for magnesium aircraft components. This project involves collaboration among the Naval Research Laboratory, ARL, Sikorsky Aircraft Corporation, NADEP-CP, the Corpus Christi Army Depot, the Army Aviation and Missile Command, the Applied Research Laboratory of Penn State University, the Australian Defence Science & Technology Organization, and the Joint Strike Fighter Program to jointly identify materials test requirements, develop and optimize the deposition of Al alloy coatings, execute the materials testing, demonstrate deposition on components, perform cost/benefit analyses, establish a production-ready facility at NADEP-CP, and prepare standards and specifications for SPD that could be used by any DoD original equipment manufacturer or depot on magnesium alloy components.

Expected Benefits: 

Qualification of the SPD coatings on magnesium alloy components of helicopters and fixed-wing aircraft would represent a key step in eliminating the currently used hexavalent chromium-containing compounds that provide surface protection. Based on failure analysis, Sikorsky Aircraft Corporation has estimated that up to 40% of the H-60 main and tail rotor transmission housings that are currently replaced in overhaul would remain in service if coated with SPD aluminum alloys. At their repair facility, this represents an annual savings of approximately $250,000 on those specific components alone. The annual cost of acquiring new magnesium alloy components throughout the Army is approximately $8 million. Extrapolating the Sikorsky Aircraft Corporation data to all components in the entire fleet of Army helicopters indicates that annual savings would be in the range of several million dollars. (Anticipated Project Completion - 2009)

Principal Investigator:  

Mr. Victor Champagne
U.S. Army Research Laboratory
AMSRL-WM-MD
Aberdeen Proving Ground, MD 21005
Telephone: (410) 306-0822
Fax: (410) 306-0806
E-mail: vchampag@arl.army.mil