February 2002

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 provides 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. More information about the program can be found at http://ctma.ncms.org/. To subscribe or unsubscribe to the CTMA Connector, send a message to listmanager@ncms.org with "subscribe CTMANewsletter" or "unsubscribe CTMANewsletter" in the subject line.

Ongoing Project News

Register for the 2002 NCMS/CTMA Working Symposium on Sustainment: Strengthening America's Military Readiness.

April 16 - 18, 2002, OMNI Hotel, Jacksonville, FL

Information and registration on the 2002 symposium can be found at the CTMA website: http://ctma.ncms.org/. Co-sponsors for this year’s event include the DoD Sustainment and Readiness Subpanel (Air Force, Navy and Army ManTech programs), the Joint Council on Aging Aircraft, the Navy RepTech program, the DoD Joint Technology Exchange Group, and the National Center for Manufacturing Sciences (CTMA program). The technical program will feature over 75 presentations highlighting current funded projects and workshops devoted to developing new project ideas for possible future funding. In addition, representatives from the DoD will discuss current issues in the sustainment of aircraft, ground vehicles, ships and submarines. A special government room rate is available at the Omni Jacksonville Hotel through March 25. To take advantage of this rate, mention “NCMS/CTMA” when registering with the hotel.

Near-Dry Machining of Aluminum

The Near-Dry Machining of Aluminum project is demonstrating the advantages, disadvantages and robustness of near-dry machining of aluminum technology by pilot applications in a high-volume tier-supplier to the automotive industry. An Ex-Cell-O Machine is now in the runoff stages at the facilities of one of the project participants. Early machining results have produced parts within a cycle time that is 50 percent faster than the current machining process used on the production floor. In addition, the use of coolant has been virtually eliminated, and better control of the chips will decrease chip interference in the fixturing of parts, thus improving part quality. Contact Jack McCabe, 734-995-4919, for more information.

Portable Thermal Spray Booth Equivalency Unit

The Thermal Spray project focuses on developing a booth equivalency unit that tracks and records spray booth conditions. The objective of this project is to transfer known good booth conditions to different booths, as well as to optimize the performance of individual spray booths. Achieving similar operating conditions across numerous spray booths is essential for quality control purposes. Previous development work demonstrated the lack of correlation between booth control set points, the booth operating conditions and the ultimate objective: obtaining acceptable thermally sprayed coatings.

The Portable Equivalency Unit has now been built and is ready for trials at facilities interested in optimizing their thermal spray capabilities. Contact Chuck Ryan, 734-995-4905, for further information.

Emerging Project Ideas

High-temperature, Lead-free Solder

NCMS held a High-temperature Lead-free Solder Workshop at its headquarters in Ann Arbor on February 14 and 15, 2002. Eleven companies attended, including OEMs, material suppliers, and assembly and test organizations. The workshop objective was to bring together interested parties and determine the need for a collaborative project to evaluate lead-free interconnect materials that can be used at temperatures reaching up to 205°C. The industry interest is in the area of joining chips and components to substrates that will be exposed to high temperature applications, such as on the engine of an automobile, a jet engine, aerospace components, deep hole drilling for the oil industry, etc. At this workshop, project scope discussions led to a focusing of initial efforts to determine the likelihood that a metal alloy or conductive adhesive technology would indeed be able to meet the characteristics required of high reliability electronics performing in these higher temperature environments. “Thinking outside of the box” will be required to achieve the project objective. In a series of ongoing conference calls, project participants will further determine the direction for the project, the project scope, additional participants needed, and alternative materials/methods to evaluate them.

This emerging project follows an earlier NCMS lead-free solder project that was completed in 1996. One of the objectives of the research from the first project was to find lead-free solder alloys that exhibited superior fatigue resistance from -55 and up to 160 degrees C. From an evaluation of 13 alloys containing different levels of Sn, Ag, Bi, Cu, Co, Zn, In, Sb, seven alloys with varying composition of the following elements, Sn, Cu, Ag, Bi, In, Sb, were used to build test hardware containing a range of components. These assemblies were thermal cycled in excess of 5,000 cycles and in some cases up to about 10,000 cycles. The alloy that exhibited the best thermal cycle fatigue was Sn-3.4Ag-1Cu-3.3Bi, followed by Sn-4.6Ag-1.6 Cu-1 Bi-1Sb. The addition of Bi to lead-free solder alloys resulted in a definite positive impact on the thermal cycle fatigue failure times. Bi containing alloys also exhibited superior performance.

Please contact Lee Patch, 734-995-4972, should you have a need for this technology, wish to understand the assembly and repair issues associated with lead free materials in electronics, or would like to help define the project scope.

New Project Ideas (click on topics to see descriptions)