Defense Primer: Acquiring Specialty Metals, Rare Earth Magnets, and Tungsten [May 24, 2019] [open pdf - 439KB]
From the Document: "Some 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 (such as integrated circuits, electrical wiring, oroptoelectronic devices) or structures (such as aircraft fuselages or ship hulls) of the military platforms and weapon systems that enable war fighting capabilities."
CRS In Focus, IF11226
Congressional Research Service: https://crsreports.congress.gov/