July 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

Rapid Prototyping

The following article for the Rapid Prototyping Project was published in the NAVSEA NEWS WIRE 01-20 (JUNE 21, 2001) "PHNSY & IMF honored for taking part in manufacturing technology program By PHNSY & IMF Public Affairs

Pearl Harbor Naval Shipyard and Intermediate Maintenance Facility (PHNSY & IMF) shared honors with some world-renowned companies last month when the command was selected as a recipient of the 2001 Collaborative Project Excellence Award from the National Center for Manufacturing Sciences. PHNSY & IMF was honored for its participation in a Rapid Prototyping Technology Advancement program for sharing and exploring new technologies as a way to quickly and economically make small quantities of otherwise expensive or hard-to-obtain specialty parts.

Other honorees included Portsmouth and Norfolk naval shipyards, NASA's Marshall Space Flight Center, Pratt and Whitney, Eastman Kodak and Honeywell.

One of the most pressing problems for both private industries and Department of Defense maintenance activities is finding fast and cost-efficient ways of producing limited numbers of specialized parts that still have "conventionally manufactured" functional properties. These parts can be made directly from a computer-aided design (CAD) file, but are more frequently reverse-engineered from an existing part.

Rapid Prototyping and Manufacturing (RP&M) technologies offer a solution. According to the center, the technologies "are capable of creating physical objects directly from digital data without manually generated numerical control programs or tooling."

Although RP&M technology has had a sweeping impact in private industry, implementation within DoD maintenance facilities has been limited by high initial investment costs and associated risks. The center's RPTA program enabled DoD facilities and other organizations to share in the costs and risks through collaboration among a broad community of industry partners.

PHNSY & IMF participation began with a visit by Ken Johnson, program executive director, on Feb. 6 and 7. After briefings and meetings with mechanics, program analysts, and production shop group supervisors, yarders identified seven pilot projects for rapid prototyping. Through the program, the Shipyard received weld rod holder caps and an injection mold tool for electronics cable connectors. Shops 26 and 67 are evaluating these items for usability and cost benefits. When the studies are done, the shipyard will seek new projects to expand participation in the RPTA Program."

Thanks to Bob Sonoda at PHNSY for sending this to us. We welcome others to forward such publicity to us.

Projects Seek Participants

Selective Corrosion Protection by Cold Gas-dynamic Spraying

In the late 1980s, researchers in Russia developed a metal coating process based on high-velocity, low-temperature gas streams achieved through use of converging-diverging (deLaval) nozzles with solid powder feedstocks of size 1-50 microns. They called this process "cold gas-dynamic spraying." One of the earliest envisioned applications for cold-spray technology was in the area of corrosion protection. This is partly due to the capability of the technology to deposit high-purity coatings of materials such as zinc and aluminum, which can act as very localized sacrificial anodes, as well as providing a degree of barrier protection. Because the deLaval nozzle produces a highly collimated beam of metal particles, it is possible to apply very localized regions of materials, without the necessity of masking or post-deposition clean-up. Several facilities are currently exploring the use of such a process in selective corrosion protection and restoration of surfaces altered by the manufacturing process, where such artifacts as weldments, mechanical deformation or abrasion have compromised corrosion protection.

While the process works in principle, technical barriers limit its widespread usage. Among these: the emergence of an infrastructure to provide systems and materials, long-term durability of the nozzles (which can erode or become clogged), and sensing and control systems which would be necessary to make the process acceptable in a manufacturing environment. We envision a possible project that will explore the potential of this technology in manufacturing and repair.

Interested project participants should contact Chuck Ryan at 734-995-4905.

High Velocity Electromagnetic Forming

Electromagnetic forming is a non-contact method of accelerating sheet metal at velocities in the range of 50 - 300 m/s. High velocity forming has many useful attributes. For example, formability can be greatly improved (to over 100 percent extension in plane strain in commercial aluminum alloys, at room temperature). In addition, wrinkling can be significantly inhibited. There are also many distinct ways the technology can be used to enable agile and rapid re-manufacture, prototype manufacture or repair. In many respects, this method is similar to explosive forming (which is a robust manufacturing technology), but it has these additional benefits: 1) the process is inherently much more controllable, and 2) there is no need to store and handle explosives. In another manifestation of high speed forming, a light and inexpensive electromagnetic coil (based on medium-gauge wire or cut sheet) can be used to deliver impulses to sheet metal with weight or fluid pressure providing the driving force for motion. This technique is similar to hydroforming except: 1) it can use lighter urethane tools to form against, 2) formability can be improved versus hydroforming, 3) more agile equipment is used, and 4) tight radii can be accomplished relatively easily.

In general, the controlled impulses from electromagnetic forming can be used to develop an approach to sheet metal that is similar to rapid prototyping. It is proposed that one or more alternatives be explored within a class of part shapes. Another possible application of high speed forming is for joining. The high impact speeds used in electromagnetic joining can also produce solid-state impact welds. Although the approach has not received any attention for repair joining, this technology has many intrinsic advantages over such repair procedures as welding in that deleterious heat affected zones are not produced. The technique is amenable to many structural cross-sections and configurations. It can also be very readily set up in a typical shop environment.

It is proposed that high velocity electromagnetic joining be developed and utilized in the following ways:

1. Design rules are required to estimate the load-carrying capabilities of crimped joints,
2. Production rules are required for fabricating the inexpensive and rapidly produced one-shot electromagnetic actuators, and more robust multi-shot actuators.
3. Demonstration structures should be produced using rules in parts 1 and 2 and destructively tested to demonstrate static and fatigue strength.

If you are interested in a possible project in this area, contact Dr. Manish Mehta, at 734-995-4938.

Puget Sound Naval Shipyard is proposing possible CTMA projects in the following areas.

We are seeking both industrial and DoD participants. Contact Chuck Ryan with your interests.

1. Aircraft Carrier Catapult Trough Drainage Stops: Develop a rubber channel that is rolled or pressed out and sealed to the deck to prevent rainwater runoff from pouring into troughs.
2. Radio Frequency Identification (RFID): RFID will improve Puget Sound Naval Shipyard's ability to track ship assets, material inventory, facilities and equipment, tools and fixtures, as well as off-station materials through real-time interface with the Shipyard's LAN.
3. Weld Positioner/Robotic Arm for Laser Welding: Acquisition of weld positioner/robotic arm will complement PSNS laser welding equipment and processes to establish a full production work cell
4. Helium Leak Test for Piping Systems: Develop/apply this technology to newly installed and modified shipboard piping systems.
5. Cold Cutting Techniques for Structures and Piping: Develop portable tools to be used for cutting large structural items and piping containing hazardous materials, and for cutting 6" - 24" diameter holes.
6. Non-Hazardous Process for Removal of Paint/Primer: Develop method to remove paint/primer from curved/irregular surfaces, voids, etc., while minimizing the amount of hazardous waste generated. Also general paint/primer removal and cleaning solvents that are environmentally friendly.
7. Ergonomically Friendly Hand Tools: Develop hand tools such as Saws-Alls and Grinders that are comfortable and safe to use for extended periods of time, not prone to vibration and repetitive motion type injuries.
8. Hand Held Device for Identification of Lead, Chromates, and Other Hazmat: Light, portable device for instant field identification of Hazmats
9. End-Prep Tools for Short Pipe Sections: Need small cutting and end-prep heads for use in space-restrictive areas in lieu of hand prep method.
10. Robotics for Tank Cleaning/Surface Prep: Automated tools for cleaning and surface prep of tanks and voids. Requires negotiating irregular surfaces.
11. Automated Propeller Machining Techniques: Aircraft carrier and submarine mono-bloc propellers are measured with sophisticated tools, but hand finished in a manually-intensive process.
12. Permanent Marking of Weld Wire: Current weld wire marking techniques do not hold up in the rigors of our industrial environment. Some form of permanent marking is needed to ensure all wire is identifiable to the welder.
13. Temporary Lead Shielding: Flexible shielding to reduce exposure levels.
14. Lead Ballast Handling System: Ingots of lead are arranged in tight spaces for ballasting. The work is heavy, awkward, and can be unsafe. A delivery system for loading the ingots that minimizes manual handling is desired.
15. Electrical Induction Heaters for Welding: PSNS currently uses 440V strip heaters with exposed elements for pre-heating of material. Electrical induction heaters are faster (hours vs. all day for pre-heat), more energy-efficient, and safer since they do not use direct radiant heat.
16. Inexpensive Fiber for Remote Source Lighting

New Project Ideas (click on topics to see descriptions)

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.