October 2000

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 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 this more useful.

Ongoing Project News:

Leak Test Technology Development

The first speed of sound (SOS) sensor test run was conducted at Jacksonville NADEP on an F-14 undergoing fuel system testing.  Using traditional methods, the Jacksonville team had predetermined two leak points as a test of the SOS system.  Not only did the new system detect each leak, but it was able to specifically pinpoint the leak site as well. 

We will be testing our second F-14 aircraft at the end of October. Other programs at the NADEP JAX have also shown interest in this technology. The benefits described to this point include:

  1. System can detect a 10X smaller leak than with conventional means. Reduces man-hours downstream after system buildup.

  2. He/Air breathable mixture is much safer than using pure Nitrogen in closed areas such as fuel tanks.

  3. One test stand can be used for various applications. No need for numerous pieces of support equipment.

  4. Programmable and automated test procedure reduces man-hours and possibility of errors.

 NCMS Contact: Connie Philips, 734-995-7051

Near-Dry Machining of Aluminum

The OSHA Standards Advisory Committee on Metalworking Fluids published its recommendations in a report on July 15, 1999. The committee recommended that the Permissible Exposure Limit be set at 0.5 mg/m3 total particulate limit, a factor of 10 lower than the current requirement. The implications of this new limit and the cost to enforce it - from the standpoint of both equipment and health surveillance - are estimated to increase the cost of manufacturing significantly. It could slow down production and drive some types of manufacturing off shore. The impact of the committee's recommendations is of particular interest to those who are responsible for the environment around machine tools.

One approach to circumventing these issues is to reduce the coolant used during metal cutting - the objective of the Near Dry Machining of Aluminum CTMA program. A number of companies have banded together under the CTMA program to pilot this technology in a production environment. Data will be gathered and analyzed to the state of the technology, particularly for long-term operation. The focus of this program is on cost related issues such as tool life, product quality and chip evacuation. If you are a member of the DoD repair and maintenance community, you are welcome to become a member of the project team. Testing will begin in January 2001 with a machine that is under construction and equipped to address the questions we need answered. 

NCMS Contact: Jack McCabe, 734-995-4919

New Project Ideas

The following ideas are being considered for development into collaborative projects.  A complete list of emerging ideas is included at the end of this newsletter.  

Harsh-Environment, High-Reliability Lead Free SOLDER

In the face of customer demands for “GREEN” products and political pressure to eliminate Pb from all electronic assemblies, there is a compelling need to develop a Pb free solder alloy and assembly processes for electronic products used in harsh environments. For electronic assembly applications at elevated temperatures above 160 degrees, the industry currently uses high lead solders for the joining of electronic components to substrates. The use conditions of these solder alloys are for operating temperatures up to 205 degrees C. Multiple industries – including the avionics, automotive, oil exploration, and traditional data processing industries – use high lead solder alloys for these harsh environment applications.

The performance criteria for a satisfactory replacement lead free solder alloy would be to exhibit equal to, or better than, 95-5 Pb/Sn at the equivalent environmental conditions. Additional research into a suitable replacement to high lead solder alloys is not only warranted, but necessary.

NCMS is seeking input and participation on a potential project aimed at addressing this challenge. Among the related issues currently being considered are the following:

  • New alloy and flux formulations

  • Component metallization

  • PCB metallization

  • Metal leachate from the new alloys

  • Repair/reworkability processes

  • Component reliability at higher process temperature

Together with interested partners, it is our intent to identify other issues, assemble a project team, formulate a scope of work and determine program deliverables.  

NCMS Contact: Lee Patch, 734-995-4972

Collaborative Visualization

This project envisions developing a proof-of-concept model for a multiple viewport, 3D imaging workstation that will allow 2 – 8 people to simultaneously view and collaborate on 3D images that will be projected without the use of cumbersome headgear or goggles, and without the expense and footprint of a CAVE or power wall environment.  NCMS is also looking for DoD interest to form a new CTMA project that would develop a miniature 3D visualization system that would allow 3D visualization in the field in natural lighting without the use of headgear, glasses or other peripheral devices.  Such a device would be designed to be "battle-ready" for tanks, boats, Hum-Vs, submarines and could be used in classes as a training device, or in the field for 3D video conferencing, 3D CAD file projection, or with remote stereo camera "robots" for battlefield reconnaissance.  Further miniaturization could place this visualization system within a briefcase. These projects would be independent from, yet complementary to, the existing Interactive Visualization project currently in progress.  

NCMS Contact: Jeff Ceo, 734-995-4936.

Strategic Machine Tool Technologies:  Propulsor Manufacturing Cell

The Naval Foundry and Propeller Center (NFPC) manufactures all of the propellers destined for the Submarine fleet.  These propellers are challenging, complex machining projects that require large amounts of metal removal and high precision 5-axes surface machining.  The new Virginia class propulsor with its many components and tighter tolerances will impose new technical challenges in metal removal rates, in-process inspection, welding work holding, and production throughput.  Addressing these issues will require a new approach to propulsor production.

Proposed Objectives:

  1. Design and install an automated propulsor machining cell consisting of:

    • 5-axes CNC milling machine with automatic spindle head and tool changer including high and low speed spindles, and high contouring speeds.

    • Multiple set-up stations on Automated Guided Vehicles (AGV) that slide the parts in the work envelope of the 5-axes machine, then transports them to inspection and welding stations.

    • An in-process inspection station, where components are automatically laser scanned for a geometric profile that will be used to accurately finish machine the parts.

    • A welding station that would quickly repair casting defects and weld other areas (confidential).  After welding, the components can be automatically returned for further machining or inspection.

    • A climate controlled enclosure to house the cell in order to minimize the effects of environmental conditions on machine accuracy.

  2. Demonstrate and validate the integrated functions that will allow the cell to produce propulsor components with minimal interruption and manual handling.

  3. Demonstrate high speed machining of nickel aluminum bronze castings and validate current basic research.

Benefits Foreseen:

  1. Integrate three production processes, which currently create bottlenecks on the shop floor, into one controlled production line that would provide flexibility and agility in production.
  2. The extension of high speed machining from aerospace aluminum production into steel and bronze machining will have an appreciable impact on the cost and delivery of propulsor components.  Current research shows a five-fold increase in metal removal rates of nickel aluminum bronze castings.
  3. Introduction of new CNC techniques like Non Uniform Rational B Splines (NURBS) interpolation will condense large programs allowing for uninterrupted machining, higher resolution and enhanced accuracy.

NCMS Contact: Jack McCabe, 734-995-4919

Other News:

 

The DoD Maintenance Symposium and Exhibition is being held 30 October - 2 November in Charleston, SC.  Further information can be found at http://register.ndia.org/interview/register.ndia?~Brochure~174

 

The Military and Aerospace Electronics Committee of the ASME Electrical and Electronic Packaging Division (EEPD) announces a workshop:

 

EEPD SYMPOSIUM/WORKSHOP

“ALTERNATIVES TO LEAD SOLDER: VIEWS, CONCERNS, AND ISSUES FOR USE IN MILITARY ELECTRONICS AND OTHER HARSH ENVIRONMENTS”

INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION

WALT DISNEY WORLD, NOVEMBER 9, 2000

 

More information and the registration form is available at http://www.asme.org

 

NCMS members believe this topic is important to the industry and the DoD, as the industry is rapidly moving toward lead-free products. However, much work has yet to be done for the harsh environment, high temperature applications. This technology is sure to impact how repair and rework is performed in the DoD. Duane Napp will be in attendance at this workshop representing NCMS. Please encourage your people to contact him.

New Project Ideas: (click on topics to see descriptions)

1 Equipment Parts Information Management System
2 Honing Auxiliary Power Units
3 UV Surface Preparation
4 Oxy Fuel Cutting Alternatives
5 Radio Frequency Locators
6 Lead Free SOLDER
7 Reliability Based Maintenance
8 On-Site Paint Destruction
9 Kinetic Spray Processing
10 Hard Chrome Process Improvement
11 Robotic Painting Optimization
12 Propulsor Manufacturing Cell
13 Non-Destructive Inspection of Composite Parts

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.