ADDITIVE MANUFACTURING is the magazine devoted to industrial applications of 3D printing and digital layering technology. We cover the promise and the challenges of this technology for making functional tooling and end-use production parts.
Issue link: https://am.epubxp.com/i/894355
NOVEMBER 2017 Additive Manufacturing FEATURE / Metal Additive Manufacturing 56 By Peter Zelinski According to Elementum 3D co-founder Jacob Nuechterlein, the aluminum alloy used in the company's newly invented met- al matrix composite (MMC) is not 3D-printable on its own. Not every metal is a candidate for use in an additive process. With this alloy, a form made of the metal will tear itself apart from internal stresses as it is built up in a laser powder-bed additive machine. But here's the thing: When a ceramic is added to the metal— that is, ceramic powder that does not melt during the build—the result is very different. The ceramic, in combination with a propri- etary process Elementum 3D developed for applying this material, makes this metal printable. More importantly, the combination of ceramic plus metal produces a strong, lightweight, heat-resis- tant material that holds considerable promise for various future applications, not the least of which is the additive production of dramatically lighter aerospace or car engine components. This new material is not a compound and not a new alloy. It is a composite, meaning its constituent materials complement one another while remaining chemically separate. Well-known composites include concrete and fiberglass, plus the carbon- fiber-reinforced plastic used in aircraft. But here is a case of a composite in which the components can be seen only under a microscope. MMCs of this type can be made by compact- ing powder in a mold, but thanks to additive manufacturing, Elementum 3D has now not only pioneered a new MMC blend, but also extended the range of applications for this class of materials into geometries that molding can't achieve. Through additive, MMCs will do more and there will be more of them. The primary obstacle standing in the way is simply the discov- ery process and the development work that every new material for AM requires—and this is the obstacle Nuechterlein expects his company to help overcome. In finding an effective process for a new material, the number of potentially significant variables is large, Jacob Nuechterlein says. His firm specializes in material development, specifically for the EOS machine behind him. The team's experience in exploring materials for this machine gives it a head start that can speed the development of a new or custom alloy. Material Advantage A firm aiming to realize the material freedom of AM introduces a metal matrix composite for DMLS machines.