Components made using metal 3D printing can be smaller and, especially, lighter than equivalent components made by conventional methods. At left is a manifold that had been used in a portable power unit, and at right is the 3D-printed version, which weighs 74% less. (Image courtesy of Aidro SrL.)
This is in contrast to machined components, where the component (typically a manifold) begins as a solid block of metal, and the materialis removed to meet requirements. The limitation to this technology is that excess material usually is left in place to save the expense of removing it, resulting in parts that weigh more than necessary. Much of the excess metal could be removed to reduce weight, but doing so would add substantial manufacturing cost that rarely can be justified by the relatively small weight reduction.
Machining also is limited to producing many desired configurations, such as oval-shaped or squared-off fluid channels that can carry the same flow as a round channel, but in less space. Passageways in conventional manifolds often must be positioned to prevent cross-drilled channels from intersecting and allow enough material between channels to provide adequate strength. Auxiliary holes drilled to connect internal passageways usually must to be plugged to prevent cross-channel flow.
Metal 3D printing in a nutshell
Metal 3D printed components build up the desired component layer by layer. The process uses a computer-controlled laser to melt each layer of metal as it is deposited to build up the part. According to Alberto Tacconelli, Managing Director at Aidro SrL, Taino, Italy, the most appropriate type of metal 3D printing for hydraulic components is powder bed fusion, either by direct metal laser sintering (DMLS) or selective laser melting (SLM).
DMLS heats the metal powder to the point that particles fuse together on a molecular level. The porosity of the sintered material is controllable. And DMLS can be used with a variety of alloys, allowing functional prototypes to be made out of the same material as production components. With SLM, the metal powder is not merely fused togetherbut is actually melted into a homogenous part by a high-power-density laser. Because of reduced porosity, parts made with SLM exhibit high strength by controlling crystal structure of the finished metal.
Furthermore, channel design can achieve greater flow within a smaller space. Passageways connecting internal channels don’t have to be machined from outside a manifold, eliminating the need for hole plugs.
Metal 3D-Printed Manifold
Aidro used this technology to manufacture a compact, lightweight manifold in a portable hydraulic power unit. The result is a hydraulic manifold that weighs about one-fourth that of its conventional counterpart machined from a solid block of metal. The 3D-printed manifold had to match up dimensionally to a previous design and also serve as the top to the HPU’s hydraulic reservoir. Without this restriction, the 3D printed manifold probably could have been made smaller, which would have reduced weight even more.
For more information on metal 3D printed hydraulic components from Aidro, visit www.aidro.it
