{"id":11349,"date":"2024-03-05T22:00:00","date_gmt":"2024-03-05T22:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=11349"},"modified":"2024-02-22T10:35:53","modified_gmt":"2024-02-22T10:35:53","slug":"3d-printing-promises-more-efficient-ways-to-make-custom-explosives-and-rocket-propellants","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/3d-printing-promises-more-efficient-ways-to-make-custom-explosives-and-rocket-propellants\/","title":{"rendered":"3D printing promises more efficient ways to make custom explosives and rocket propellants"},"content":{"rendered":"\n
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\n 3D printing can be used to build with all kinds of materials \u2013 even those that go \u2018boom.\u2019\n kynny\/iStock via Getty Images<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\nMonique McClain<\/a>, Purdue University<\/a><\/em><\/span>\n\n

Imagine you\u2019re driving to work on a rainy day, when a distracted, reckless driver hits your car out of nowhere. With a \u201cboom,\u201d an air bag deploys faster than you can blink your eyes<\/a> to save your life. <\/p>\n\n

That air bag deployed rapidly thanks to an energetic material called sodium azide<\/a>, which generates nitrogen gas during a chemical reaction to inflate your airbag. But what\u2019s an energetic material? <\/p>\n\n

Energetic materials include propellants, pyrotechnics, fuels and explosives<\/a>, and they\u2019re used in all sorts of settings. <\/p>\n\n

Uses of energetic materials include flares<\/a>, matches<\/a>, solid rocket boosters<\/a>, gun propellants<\/a>, hot thermite welding<\/a> used to fuse materials together, fireworks<\/a> and the explosive special effects<\/a> in your favorite action movie. <\/p>\n\n

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\n Propellants help rockets blast off.<\/span>\n U.S. Air Force\/Joe Davila<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\n

Energetic materials come in many shapes and sizes, but they\u2019re often in a solid form and release a lot of energy through burning or exploding<\/a>, depending on their shape and the conditions they\u2019re operating in. <\/p>\n\n

I\u2019m a mechanical engineering professor<\/a> who studies energetic materials<\/a>. Making energetic materials isn\u2019t easy, but developments in 3D printing could make customization easier, while allowing for more potential scientific applications. <\/p>\n\n

The role of geometry<\/h2>\n\n

How energetic materials are made affects the shapes that they come in and how they release energy over time. For example, solid rocket propellants are made similar to a cake<\/a> where a stand mixer stirs the \u201cbatter,\u201d which is mostly made of ammonium perchlorate, aluminum and a rubbery binder<\/a>, before it\u2019s poured into a pan. The \u201ccake\u201d solidifies in the pan while it bakes in the oven. <\/p>\n\n

Typically, rocket propellants have a cylindrical shape, but with a rod in the center. The rod<\/a> often has a specific cross-sectional shape<\/a>, like a circle or a star. When the propellant solidifies, the rod is removed, leaving the core shape behind. <\/p>\n\n

The core shape affects how the propellant burns, which can affect the thrust of the motor it\u2019s used in<\/a>. Just by changing the central shape of the propellant, you can make a motor accelerate, slow down or maintain its speed over time. <\/p>\n\n

But this traditional \u201ccake baking\u201d process limits the shapes that you can make. You must be able to remove the rod after the propellant solidifies, so if the rod\u2019s shape is too complex, you might break the propellant, which could make it burn erratically. <\/p>\n\n

Designing propellant shapes that make rockets go faster or fly farther is an active area of research, but engineers need new manufacturing methods to create these increasingly complex designs.<\/p>\n\n

3D printing to the rescue<\/h2>\n\n

3D printing<\/a> has revolutionized manufacturing in a variety of ways, and researchers like me are trying to understand how it can improve the performance of energetic materials. 3D printing uses a printer to stack up material layer by layer<\/a> to build an object. <\/p>\n\n

3D printing allows you to make custom shapes, print multiple types of material in one part, and save money and material. <\/p>\n\n

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