5 Military Technologies Reliant on Rare Earth Elements

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The first season of the award-winning Netflix political drama House of Cards focused on the strategic value of rare elements, specifically samarium. Although the United States dominated the mining of rare earth elements in the 1960s through the 1980s, it is now mostly reliant on imports from China for such commodities. This is obviously a troubling national security situation for the U.S. Despite their name, many of the 17 elements that compose the recognized category known as rare earths — the lanthanides on the periodic table, plus yttrium and scandium — are relatively common in the Earth’s crust. These exotic elements aren’t typically concentrated in large deposits however, making extraction difficult. Rare earths are becoming more prevalent in electronics and computers, including those found in current and future weapons systems. Here are some of the key military applications that are reliant on rare earth elements.

 

5. Guidance and Control Systems

Smart munitions have been a great improvement over old laser-guided munitions.

Joint Direct Attack Munitions missiles, here aboard the USS Harry S. Truman aircraft carrier, rely on rare earth elements for high-performance guidance systems.

Modern-day smart weapons rely on sophisticated motors and actuators to steer them toward their targets. To accomplish this feat, these missiles and bombs incorporate rare earth elements such as terbium, dysprosium, samarium, praseodymium and neodymium. These are necessary for high-performance guidance systems. Neodymium is used in NIB (neodymium, iron and boron) supermagnets, and samarium-cobalt magnets resist corrosion and can operate at high temperatures. The bulk of the world’s production of neodymium comes from China, although central Turkey also maintains the largest proven reserve of elemental boron in the world. China also imposed strict strategic materials controls on rare earth elements including neodymium as well in 2010, causing the price of neodymium to peak at $500 per kilogram in mid-2011.

 

4. Defense and Electronic Warfare

Airman inspect an AN/ALQ-184 Electronic Attack Pod, an electronics jamming device that relies on the yttrium for operation.

Airmen inspect an AN/ALQ-184 Electronic Attack Pod, an electronics jamming device that requires yttrium for operation. Credit: U.S. DoD

Many modern defense electronics systems require a portable high-capacity power source, or the ability to use high-energy storage and amplification. These include storage batteries and electronic jamming devices (known as ECM pods) used in the field, as well as more exotic defensive systems in development, such as microwave-generating Area Denial Systems and Electromagnetic Railguns. Yttrium-iron-garnet (YIG) is a key material used in electronic countermeasures for what are known as dispersive delay lines and microwave filters. These filters are robust and guarantee a high signal-to-jamming ratio and are an essential component of electronic warfare systems. The United States currently has no production of yttrium, and the Department of Defense projected a 93-ton shortfall of yttrium for military requirements in 2013. China accounts for 95 percent of rare earth production worldwide, and yttrium is found in ores such as fergusonite and monazite.

 

3. Electric Motors

The U.S. Navy’s new Zumwalt class of guided missile destroyer relies on rare earth elements for its batteries. Credit: U.S. Navy

The U.S. Navy’s new Zumwalt class of guided missile destroyers requires rare earth elements for its batteries. Credit: U.S. Navy

As Tesla ramps up production on its promised electric car, expect the demand for rare earth super magnets to rise. The military is also expected to become a major consumer, as the need for the next generation of electric motors grows. These motors feature compact and powerful magnets, and require such rare earth elements as terbium, dysprosium, samarium, praseodymium, and neodymium. Systems such as the CMPS (Common Modular Power System) Future Combat vehicle, and the U.S. Navy’s Zumwalt DDG 1000 guided missile destroyer will also require rare earths in the next generation of electric motors, as will Hub Mounted Electric Traction Drives and Integrated Starter generators currently under development. China is by far the largest producer of samarium at 120,000 tons per year, versus U.S. production of only 5,000 tons. China also controls the market in the other elements needed for electric motors; a GAO report from 2010 noted that China produces 75 percent of the world’s neodymium iron boron magnets, and 60 percent of the world’s samarium cobalt magnets.

 

2. Targeting and Weapons Systems

The Humvee-mounted Laser Avenger uses yttrium, europium and terbium.

The Humvee-mounted Laser Avenger uses yttrium, europium and terbium.

Modern-day weapons systems rely on high-powered lasers for targeting and acquisition. These include air- and vehicle-based laser systems, and such exotic weapons platforms as the SaberShot Photonic Disruptor, and the Humvee-mounted Laser Avenger used to counter Improvised Explosive Devices (IEDs). These rely on rare earth elements such as yttrium, europium and terbium to achieve high-powered energy resolution and amplification. And Europium has been used for years in the red phosphors of computer monitors and television screens.

 

1. Communications

The air traffic control center aboard the USS Abraham Lincoln. Credit: U.S. Navy

The air traffic control center aboard the USS Abraham Lincoln. Credit: U.S. Navy

An often-overlooked facet of military infrastructure, communications are essential to providing military commanders with an overall picture of the battlefield. These now incorporate numerous rare earth elements, including europium, lutetium, lanthanum, yttrium and neodymium. Terbium is also used in naval sonar systems, and rare earth elements are also used in radiation and chemical detection systems such as the Multipurpose Integrated Chemical Agent Alarm. Rare earth permanent magnets are used in waveguide tubes that amplify microwaves and are incorporated on radar systems and satellites. Line of sight laser communications are also finding applications as well due to their faster transmission speeds, and Erbium-doped fiber amplifiers and signal repeaters can transmit large amounts of data quickly over a vast area.

 

One More: Jet Engines

The F-22 has been dogged by controversy in recent years.

The rare earth element rhenium is a key component of jet engines.

Rare earth elements used in modern-day jet engines are especially crucial and of strategic value. Rhenium is used as an alloy mixture added to molybdenum and tungsten, and erbium is added to vanadium to lower its hardness and make it more malleable for use in vanadium steel. Erbium was one of the six rare earth shortfalls that were identified under the 2013 Strategic and Critical Materials Report on Stockpile Requirements, and the primary source of erbium is now the ion-adsorption clays of southern China. F-16 and F-15 jet engines contain 3 percent rhenium, while next generation fighter jet engines which will be used in the F-22 Raptor and the F-35 Joint Strike Fighter will utilize double that amount. Jet engine makers General Electric, Rolls-Royce, and Pratt & Whitney account for over half of rhenium use worldwide, although there are plans to make next-generation engines that incorporate much lower amounts of the rare earth element. Chile has the largest known rhenium reserves, and the element is found along with copper deposits.

Written by

David Dickinson is a backyard astronomer, science educator and retired military veteran. He lives in Hudson, Fla., with his wife, Myscha, and their dog, Maggie. He blogs about astronomy, science and science fiction at www.astroguyz.com.