[20211215]IF11226_防务基础：获取特种金属和敏感材料.pdf

https:/crsreports.congress.gov Updated December 15, 2021Defense Primer: Acquiring Specialty Metals and Sensitive MaterialsSome metals (such as titanium and tungsten) and metal alloys, as well as strong permanent magnets known as rare earth magnets, are critical to U.S. Department of Defense (DOD) operations. These materials are frequently integrated into components (e.g., integrated circuits, electrical wiring, or optoelectronic devices) or structures (e.g., aircraft fuselages or ship hulls) of the military platforms and weapon systems that enable warfighting capabilities. A rare earth element is one of 17 chemical elements, including the 15 metallic chemical elements with atomic numbers 57 through 71, as well as the chemically similar elements scandium and yttrium. These materials are considered rare in spite of their relative abundance throughout the Earths crust, as the extraction and production of such materials can be difficult and costly. Rare earth magnets produced using rare earth elements are the strongest known permanent magnets. There are few, and, in some cases, no known alternatives for many of these materials, which often have unique physical properties, such as high