In aerospace parts manufacturing, it is often considered difficult by machine shops of all sizes to find an expert source for high-speed machining information and laboratory and testing service for metrology. Yet, an answer has been around for 100 years.

The National Institute of Standards and Technology (NIST) is a laboratory under the Department of Commerce which formerly was the National Bureau of Standards since the Congressional Charter in 1901 (see NIST website ) . The NBS was the first official government laboratory, keeping all measurement standards for the United States…everything from the second to the kilogram.

NBS evolved into NIST, with the official name change occurring in 1988. It now has seven specific laboratories of study. Along with Physics Laboratory, Chemistry Laboratory, and Materials Science and Engineering Laboratory is the Manufacturing Metrology Division. The main purpose of this division is to better develop and examine the measurement of manufacturing processes, including aerospace parts manufacturing .

The MMD group at NIST helps companies to better understand the potential of effective processes, to model them and to control them so they can be used more efficiently. There are also other operations at NIST that actually do machine tool characterizations , which study machine tool relationships and responsiveness relative to geometrics errors and thermal errors linked directly back to the standard of the meter.

Aerospace Manufacturing Beginnings

NIST began officially looking at aerospace manufacturing seven years ago, though other individual aerospace projects went on prior to that date. More recently, the group started a high-speed machining program.

Boeing was one of the first companies interested in having NIST as a research partner, and the Manufacturing Metrology Research Division and the Instrument Maker’s Shop at NIST got together and purchased a Makino A55 for shop floor aerospace manufacturing research and testing.

There were two primary goals for acquiring the Makino A55 . One was it could make parts for other NIST people and operations , and secondly was that the Research Division would have use of it to conduct sponsored research from external companies and corporations as well as internal projects.

The first project NIST did for Boeing was related to the speed brake on the F15 Fighter aircraft , which is still considered by many at NIST to be one of the more spectacular high-speed machined aerospace par ts they have ever seen. It began as a ten foot x ten foot x six inch slab of aluminum , high-speed machined from about 3,000 pounds down to 110 pounds by high-speed machining to make the F-15 speed brake.

Estimates from Boeing are that the cost of the part was trimmed by nearly one-third of the cost to make the former composite par t of similar performance. The only difference between the two was that the aluminum part was slightly higher in mass than the composite par t . While they we r e originally interested in how they could lighten the weight of the part , the lessened manufacturing cost and elimination of assembly made up for the small weight increase.

Current Aerospace Activities

In aerospace manufacturing , NIST is involved in several areas of research due to the continuing challenges brought about by demands on manufacturer and supplier processes and production times . And , the organization offers a variety of technical assistance to U. S . aerospace firms who want to enhance their competitiveness in the global marketplace.

One area is mechanical and dimensional measurements, including engineering metrology techniques and standards. The technically complex task of aerospace design and manufacturing needs uniform standards to ensure swift production and state-of-the-art equipment and parts .

Ongoing materials and materials processing studies constantly review the innovative use of ceramics and other metals to provide strong, lightweight and durable aerospace parts . Manufacturing processes on characterization and performance improvements on machining systems as well as predictive process engineering are also underway.

Systems integration and interoperability involves the open architecture control of manufacturing systems . This helps ensure that computer-controlled manufacturing processes speak the same language, and that computer-aided design systems properly communicate the data, so that aerospace manufacturers spend less time programming and more time manufacturing.

The Future of Aerospace Research

High-speed machining of stronger materials such as titanium and hardened steels is a challenge to many machine shops, much more so than the more versatile aluminum . But there is a range of materials between the hard materials and aluminum that is being researched for its high-speed machinability.

These metals, such as nickel - aluminum - bronze (C95800) and composite alloys , can provide similar benefits to aluminum but are not as harsh in wearing tools as are the titanium and hard steels. They often encompass the benefits of lightweight aluminum with the strength of titanium/steel. They are being used in other military applications, and are being tested in aerospace machining. These other military parts are often hand-finished in critical areas because the castings are so huge…up to 110,000 pounds…and the machines capable of machining these size castings are not fast enough to do the type of high-speed machining which is currently being done in the die/ mold industry. The machines need the small stepovers and high-speed motions in order to create finishes that don’t have to be completed by hand.

NIST studies with the Navy are currently underway relative to making a transition to high-speed machining for such large parts . And NIST does not believe it will be long before spectacular giant castings are being high-speed machined.

Tool wear is also being studied by NIST on many of these light and medium weight metals. Initial results show that a window of speeds is available for individual application consideration relative to high-speed machining. And , these results also show that as long as a machine stays within the speed window, reasonable tool wear and quality machining are both still possible.

Surface speeds in nickel - aluminum - bronze are about 15 meters a second with interrupted cutting. With a three-quarter inch cutter, which translates to 15,000 rpm , which is extremely fast for machining nickel - aluminum - bronze. NIST indicates through these studies that the future of expanding speeds in high-speed machining with various materials is just beginning.

For additional information about NIST, the National Institute of Standards and Research, contact them by phone at 301-975 NIST (6478). Or, visit their Website at www.nist.gov.

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