The ability to develop, prototype, “fit test” and deploy products quickly and with maximum program success is integral in military applications. Atrenne is 3D printing with aluminum alloy to enable the creation of complex parts without the design restrictions that accompany mainstream manufacturing, among other benefits.
Atrenne is using Metal Additive Manufacturing (MAM) — metal 3D printing — to give mechanical engineers the freedom to create complex parts without the design constraints of traditional manufacturing methods.
MAM can also use aluminum alloys, the materials of most electronic systems chassis deployed on aerospace and defense platforms, delivering the same set of advantages for system chassis, as these materials deliver an outstanding combination of structural strength, lightweight, and thermal conductivity.
Atrenne’s expertise is centered on providing innovatively designed and customized solutions for defense electronics. The company is the first to market with an aluminum alloy 3D printed chassis, as recognized by the Military and Aerospace Electronics 2021 Technology and Innovators Awards.
Off-the-shelf products have limited utility in defense programs. While standards-based components are an essential starting point, almost all deployed systems require some level of customization. Atrenne’s 3D printing capability means it can work with prime contractors to develop and deliver customized, innovative, and cost-effective chassis on time and on budget.
This printing works by addressing very thin layers of metal powder with a laser beam that fuses the particles together. Each layer of metal powder is approximately 2 thousandths of an inch thick, or half the thickness of a human hair. The laser fuses just the particles that define the design’s cross-section for that layer, then another layer of powder is put down and another defined cross-section fused.
This automated process, moving layer by layer, is used to complete a chassis and results in a single metal piece that matches the CAD model input with extreme precision. Shapes and contours in the design are not limited by the capabilities of a CNC machining tool and there are literally no joints between sections because there are no separate sections.
Initially seen as only a prototyping technology, 3D printing has matured rapidly and is currently being used, with great success, for production components in the aerospace and defense, automotive, and biomedical industries.
Examples range from air transport rack (ATR) enclosures, hip cup replacements to engine manifolds in high-performance cars. The underlying economics make 3D printing technology well-suited for prototypes, one-off custom parts, and low-volume production runs.
Advantages of 3D-Printed Chassis
Reduced Development Time — The most obvious advantage is a significantly reduced system development schedule. After completion of the CAD design, a new, custom-designed chassis can be created using 3D printing in about six weeks. This compares with roughly 26 weeks for a chassis created from milled sections joined via dip brazing.
Faster “Fit Tests” — 3D printing can create a chassis to fit any defined space within a platform. The fast development time means that a prime contractor can get something tangible in front of a customer during a project’s initial stages. This builds confidence and allows a physical fit check to ensure that the chassis design is compatible with the platform in terms of dimensions, cabling connections, etc.
Increased Program Success — Constructed from aluminum alloy, the same chassis used for the fit check can also be deployed after integration of the backplane, electronics, and power supplies. 3D printing not only means that any required physical changes are identified early, but also that a modified chassis version incorporating those changes can be created without delay. Success is achieved by being able to identify and address issues quickly.
Because a 3D-printed chassis is a single, monolithic unit, there are no anomalies associated with seams between sections. In contrast, brazement seams sometimes have tiny holes that make a chassis less than watertight.
One of the most exciting characteristics of 3D printing is that chassis designers can implement innovative material shapes. Lattice structures are the prime example, delivering strength with greatly reduced weight, as well as outstanding heat dissipation based on huge increases in exposed surface area.
