June 2001

Welcome to The CTMA Connector, a monthly newsletter designed to provide news and ideas about the Commercial Technologies for Maintenance Activities (CTMA) program. The CTMA program is a joint Department of Defense/National Center for Manufacturing Sciences (DoD/NCMS) effort promoting collaborative technology development between industry and the DoD maintenance and repair facilities. This newsletter highlights ongoing projects, serves as a forum for promoting new project ideas, and shares other news of interest to the program. Our goal is to stimulate your participation and solicit your input. Feel free to submit items for the newsletter as well as any suggestions to make it more useful.

Ongoing Project News

Portable Thermal Spray Booth Equivalency Unit - 
Seeking Depot Facilities to Demonstrate the Technology

Anytime a production facility has to transfer its process from one booth to a different, even adjacent, booth, the transfer typically results in some downtime and substandard first part output, due primarily to the tuning requirements of each individual spray booth. In spite of modern controls, it is difficult to replicate the spray parameters of booth “A” when transferring to booth “B” without additional knowledge of the spray dynamics for each system. This project characterizes the hidden elements of the booth itself by monitoring the critical parameters necessary for thermal spray processing. Once these parameters have been mapped with their respective coatings requirements, the booth becomes tunable and, ultimately, provides high-quality, productive spraying to support manufacturing. Regardless of whether plasma spray or high-velocity oxygen fuel (HVOF) processes are used, booth balance is a critical process parameter. The booth equivalency unit is now ready for demonstration within the DoD maintenance community. The industry team will come to your facility and tune your spray booths for optimal performance. If your facility is interested in participating, please contact Chuck Ryan at 734-995-4905.

Near Dry Machining of Aluminum

Jack McCabe, NCMS Vice President of Technology, presented a paper titled "Performance Experience With Near-Dry Machining of Aluminum" at the annual meeting of the Society of Tribologists and Lubrication Engineers in Orlando, Florida, on May 23, to a gathering of well over 1,000 attendees. The paper was based on the ongoing CTMA project Near-Dry Machining of Aluminum. Under the program heading of Metalworking Fluids, six technical papers were presented on dry and near-dry machining at this well-attended conference. Despite the great interest in dry and near-dry machining, the CTMA paper was the only one containing data relevant to assessing the feasibility of near-dry machining in production. Based on the information presented at this meeting, both Germany and Japan appear to be well ahead of the U.S. in applying near-dry machining in factories. Consequently, the CTMA Near-Dry Machining of Aluminum program will continue to emphasize the commercial readiness of this technology to the Depot community.

Projects Seek Participants

Wiring Integrity System

Wiring is a complex system that includes insulated power and signal conductors, fiber optics, connectors, protection devices (circuit breakers, current limiters, and fuses), and power distribution and control components. In an aerospace vehicle, the wiring system performs vital functions such as electrical power, control signal, and information distribution, and is the infrastructure linking electrical, electromechanical, and avionics subsystems. Wiring has emerged as a critical safety-of-flight system because of the increasing complexity, high density, and critical interface between electrical and electronic subsystems. The aging effects experienced by wiring systems are accumulated damage from exposure to chemical, thermal, electrical, and mechanical stresses over time. The operational environment, installation, and maintenance practices most often induce these aging mechanisms. Wiring failures often appear as broken conductors, failed connector interfaces, and damaged insulation, which can disrupt electrical signals, cause short circuits, or lead to arcing. The Navy currently expends approximately 1.8 million organizational-level man-hours annually on troubleshooting and repairing aircraft wiring systems. Approximately 1,077 mission aborts and 147,674 non-mission-capable (NMC) hours per year are due to wiring incidents. In-flight electrical fires related to wiring failures are occurring in Navy aircraft at a rate of approximately two per month. A recent study on Air Force aircraft mishaps or accidents revealed that of all electrical system related mishaps, 43% were related to the wiring interconnection system.

It is incumbent on the aviation community to become more proactive in wiring system sustainment issues, emphasizing safety, reliability, diagnostics, physics of failure and prognostics, and development of tools that can result in extended and predictable failure-free operating periods.

NAVAIR recently conducted initial testing of six well-known off-board commercial wiring diagnostic and prognostic technologies for the purpose of identifying potential elements of a wire integrity program. Recommendations included inserting new technology into the Navy depots that incorporate standing wave reflectometry (SWR) and an automatic wire analyzer (AWA), using specialized circuit analyzers that can identify, localize, and verify aircraft wiring malfunctions and system modifications.

The benefits resulting from the insertion of this technology include, but are not limited to:

  • Open-ended hardware and flexible software architecture capable of accepting technology enhancements and linking to existing maintenance databases

  • Wire system mapping capability including the ability to generate on-demand schematic diagrams

  • Detection of degenerative conditions that could lead to a wiring failure, and condition-based monitoring of wiring and electrical distribution system integrity

  • Reduction in man-hours required to troubleshoot and repair aircraft wiring discrepancies

  • Accurate tracking of maintenance actions, failures, location data

  • Reduction of in-flight wiring-related safety incidents (arcing, fire, etc.)

  • Improved reliability of the wiring and electrical system and the increased mission availability of the aircraft

CTMA is extending an invitation to military depots, technology insertion organizations, and industry partners to unite with NAVAIR, Eclypse, and CTMA to propose the full implementation of a Wiring Integrity System. To express your interest in participating, please contact Gary Burkart at 612-839-4567.

Enhanced Plasma Nitriding for Reduced Turbine Engine Maintenance and 
Repair Costs

Enhanced Materials Technologies, Inc. (EMT) is commercializing an enhanced plasma nitriding (EPN) process (U.S. patent pending) for materials treatment, with application to turbine engine repair. EPN is an improved version of the commercially mature conventional plasma nitriding processes in use today, and produces durable erosion- and corrosion-resistant surfaces on metals without decreasing their fatigue life. The key improvement for EPN is low processing temperature: treatment occurs at temperatures less than 500°C. This is several hundred degrees lower than temperatures used during conventional plasma nitriding, and ensures that substrate heat treatment or anneal condition is not compromised. Even at these reduced temperatures, EPN causes rapid formation of a hard nitride surface supported by a nitrogen diffusion zone. The hard surface provides erosion and corrosion resistance, yet, at the same time, compressive stresses in the diffusion zone increase rather than decrease the fatigue life of the treated parts. EPN process conditions can be varied to favor formation of the diffusion zone or the nitride surface, depending upon specific needs for different applications. Note that unlike coatings, EPN does not change part dimension.

On cold-section parts, EPN provides the corrosion and erosion protection of titanium- nitride coatings yet increases rather than decreases fatigue life and allows spot repair of damage without stripping. On nickel-based, hot-section parts, EPN has potential for producing durable and spot-repairable surfaces that could:

  • Simplify the application of thermal barrier coatings by eliminating the bond coat
  • Increase bond coat oxidation resistance
  • Eliminate or reduce difficulties associated with stripping and repairing thermal barrier coatings
  • Extend the service life of hot-section parts that are protected by thermal barrier coatings.

See the EMT Web site for more information.

EPN is applicable across all gas turbine engine applications, including industrial, marine, and aviation.

We are seeking additional industry partners. Please contact Gary Burkart at 612- 839-4567 if you are interested in participating.

Other News

NCMS Solicits DoD Base Interest on Steel Technologies and R&D Needs

NCMS hosted an Executive Forum on June 12 with the objective of establishing research and development/technology innovation priorities and exploring opportunities to initiate collaborative programs as well as pursue funding to address these common priorities. This event, attended by 26 leading industry representatives from the Midwest, builds on an already established Joint Industry Alliance (JIA) initiative among representatives of the steel, forging, and heat treating industries, and is intended to expand these efforts to strengthen the technological effectiveness of the steel value chain and its products. The list of prioritized projects will be published soon for soliciting further end-user and industry interest. This forum follows a successfully launched project entitled "Quantitative Measurement of Steel Phase Transformations" (http://steel.ncms.org) that was started in January with participation by 14 members of the JIA and several national laboratories. For more infomraiton, please contact Dr. Manish Mehta, NCMS Executive Director, Industry Forums at 734-995-4938, or visit http://jointindustry.ncms.org.

New Project Ideas (click on topics to see descriptions)

1 Equipment Parts Information Management System
2 Oxy Fuel Cutting Alternatives
3 Radio Frequency Locators
4 Reliability-Based Maintenance
5 3D Laser Scanning System
6 Robotic Painting Optimization
7 Propulsor Manufacturing Cell
8 Lead Free Solder
9 Composites Scarfing Robot
10 Laser Paint Stripping
11 Retrograde Part Identification
12 Honeycomb Bonded Structures
13 Advanced Electronic Noise Cleansing
14 Laser Ultrasonic Inspections
15 E&I Process Improvements
16 Wiring Integrity System
17 Enhanced Plasma Nitriding
18 Near Net-Shape Manufacturing Cell
19 Robotic Coil Winding
20 Treatment of Wastes Using Plasma Arc
21 Damage/Wear Assessment

We appreciate your feedback. Please contact Chuck Ryan with suggestions or input on other topics that would be of interest to you in this newsletter. The CTMA Program is sponsored by the Department of Defense; the content of this newsletter does not necessarily reflect the position or policy of the government; no official endorsement should be inferred.