April 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 will give you selected highlights of ongoing projects, serve as a forum for promoting new project ideas, and share 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.

Help Define the 2001-2002 CTMA Project Agenda

The 2nd Annual CTMA Program Symposium is being held Tuesday, 8 May, in Hilton Head, SC. It's not too late to participate and contribute to defining the CTMA project agenda for 2001-2002. Register online at http://ctma.ncms.org/symposium2001 or by calling Beth Bolog at 734-995-7962. The schedule of symposium events follows.

Ongoing Project News - Recent Project Completions

Manual Arc Welding Control

The United States Marine Corps (USMC) repairs and rebuilds its assault vehicles in the Albany, Georgia, USMC depot weld shop. To minimize weight, some of these vehicles use thick-walled aluminum panels; others use thin-walled steel panels. Joining either of these panel types is difficult and requires a high level of manual welding skill. Flaws in the joint, such as gas pockets or inclusions, are not usually apparent until the results from an x-ray or other tests become available. Any weld section found to contain a flaw must have the weld ground out, replaced, and re-inspected. This process is unavoidably time consuming and expensive, but it is the state of the art at the Albany depot as well as in most advanced industrial facilities.

The cycle of weld–inspect–weld could be circumvented if the welding process could be certified. This project developed enabling technology for weld flaw avoidance and successfully transitioned the technology into a commercial product. The product is a monitor that is a significant step toward process certification for gas metal arc welding. By sensing the following four parameters and relaying information to a welder, the monitor helps welders avoid flaws:

• Current

• Voltage

• Gas flow rate

• Weld wire feed rate.

The weld monitor, which is now commercially available under the trade name ARC Agent^® 2000, stores the data of the four sensed parameters in a PC where they are compared to the signature bands of flawless welds. If any parameter drifts out of these bands, the welder is alerted. One alert method provided to the depot is a welding helmet fitted with small red and green light-emitting diodes (LEDs).

The welder can see the lights, mounted inside the helmet, by peripheral vision. If a sensed parameter strays outside preset bands, the green light goes out and the red light is illuminated. Not only is this an effective way to alert the welder in a noisy environment, it is also useful technology for training new welders.

The following three major items were delivered to the Albany depot:

1. Two complete weld monitoring systems. Unit “a” was installed for training and welder certification. Unit “b” was configured as a portable system to service any welder’s workstation. These units include:
   • Unit “a”: A standard PC, a weld monitor, peripherals, and ARClient^® software, mounted in an enclosure and operating in a network configuration
   • Unit “b”: A PC, weld monitor, peripherals, and ARClient^® software, mounted on an industrial cart
2. Two helmets equipped with man–machine interface technology
3. On-site technical support and training.

Monitoring provides two basic benefits:

1. It reduces welding costs
2. It provides an effective basis for training and certification.

In one study, one certified welder using the monitoring equipment improved the quality and quantity of his output by $7,000 and avoided $3,000 in costs due to material, inspection, and rework. The total cost avoidance per year was estimated at $10,000 per year per welder.

Embedded Decoupling Capacitance (EDC) Project

Electronic products are increasing rapidly in component packaging density and speed. These advances are placing increasing demands on the interconnect structure to provide not only higher wiring capacity, but also better electrical performance. The printed wiring board (PWB) structure itself is becoming increasingly more important in achieving good signal integrity and meeting standards for radiated emissions.

The need for power-ground decoupling capacitance is nearly universal in electronic circuits. Today, this need is satisfied through discrete chip capacitors. However, as circuit designs increase in speed, the effective use of decoupling capacitors is becoming more difficult to achieve. Decoupling capacitors also require valuable amounts of PWB surface area, consuming up to 50% of the total board area. The increasing packaging densities are creating a desire to free up valuable surface real estate currently occupied by discrete capacitors. New capacitive materials, physically and chemically compatible with standard fire-retardant grade 4 laminate (FR-4) material, are being developed as one potential solution to this challenge.

The goal of the EDC Project was to evaluate the performance of distributive embedded capacitance in circuit boards for power supply decoupling and electromagnetic interference (EMI) suppression and to compare the results with standard surface mount technology (SMT). To achieve this goal, it was necessary to demonstrate that available EDC materials are manufacturable, that they have the physical properties to electrically perform as discrete capacitors do, and that PWBs containing them are reliable. It was also important to understand power supply decoupling, and to develop the ability to predict how and when embedded capacitance will work for a given circuit design. The total program value was nearly $1,107,000, with an industry cost-share ratio of 6:1.

You may order copies of the EDC final report on-line at www.ncms.org, or contact NCMS Customer Care, customercare@ncms.org

New Project Ideas

Two new project ideas are presented for your consideration. If you are interested in either project, contact Chuck Ryan.

The repair of aircraft composites is a manual process that subjects workers to adverse working conditions, requires workers with great skill, and often results in high levels of repeat repair work due to error. Additionally, current repair techniques often require excess material to be removed, thus affecting the weight and balance of an item.

This proposed project would develop and prototype a lightweight and portable automated composite repair tool capable of scarfing composites on aircraft contours. Deliverables would include the development of a robust automated tool that can, with a high degree of repeatability, scarf composites in an industrial environment and on or near the aircraft.

Expected benefits from this project would include:

• Improved repeatability of the repair process
• Reduced labor hours
• Reduced repair fallout.

Environmentally Friendly Removal of Coatings and Finishes Using Laser Energy

The removal of coatings and finishes from systems and components is a necessary step in maintenance and operational sustainment. Often, the processes are labor intensive, environmentally challenging, and variable.

Current repair processes involve the complete removal of the paint from the surface, which results in the generation of a secondary hazardous waste. Repair parts may also require chemical stripping of the anodized coating from the component through the use of sodium hydroxide, which involves hazardous waste disposal. Damaged areas are cleaned and repaired, then machined or hand sanded to a final finish. The components are re-anodized and then re-painted. To accomplish the operation, the repair component often requires a baking procedure that metallurgically ages the aluminum alloy, thus possibly limiting the life of the component.

In helicopter blades, the paint needs to be removed from each blade. An excessive amount of labor is consumed in hand sanding due to the fiberglass surfaces of the blades. The process is imprecise and often results in damage to the underlying composite structure.

This proposed effort will determine if laser coating-removal technology offers the potential for cost-effective improvement to numerous maintenance tasks. Commercially available systems must be evaluated, data for environmental permits must be collected, and specifications must be prepared to ensure that these products meet Navy needs. A laser-based cladding solution has already been implemented at the Naval facility in Keyport, Washington, for local repair of torpedo components. The system has saved the Navy more than $800,000 since installation and paid for itself in the first six months of operation. Because of that success, Keyport is aggressively pursuing the next step in laser-based repair operations - the localized removal of coatings (powder coat epoxy and/or underlayer) that surround the damaged area.

Expected benefits from this project include:

• Reduced cost of repair

• The elimination of existing blasting- and chemical-based coating removal operations

• Improved shop artisan morale by eliminating blasting operations, which must occur in a hot and dirty environment where personal protective equipment is required for worker safety

• Improved quality and consistency of repair; thereby reducing the amount of rework

• Reduced health and safety concerns for the artisan

• Reduced usage of hazardous materials – sodium hydroxide, anodize plating process, acetone

• The elimination of secondary waste generation and subsequent need for disposal.

Calendar of Events

NCMS 2001 Conference To Focus on Game Changers

The NCMS 2001 Conference, being held May 6-8 at the Hilton Head Marriott Resort in Hilton Head, South Carolina, offers a “think tank” forum at which knowledgeable speakers and conference participants can interact to discuss the game changers that will come into play in building our preferred future. The purpose of this conference is to challenge our images of the future in an energized, exciting, and stimulating environment. Setting the stage for this environment will be keynote speaker Glen Hiemstra, whose work as a futurist is widely known and respected through his broad experience as an international speaker and consultant on future planning for enterprises. Mr. Hiemstra offers insight into surprising developments shaping the 21st Century, and then goes beyond that to the deeper challenge of understanding our new world and creating our preferred future.

Project Idea Table: (click on topic to see its description)

If you have interest in any of the projects listed below, contact Chuck Ryan at 734-995-4905.

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 the information in this newsletter does not necessarily reflect the position or policy of the government; no official endorsement should be inferred.

^TM LENS is a registered trademark of Sandia National Laboratories.