Heraeus Additive Manufacturing has overcome the technical obstacles in the additive manufacturing of highly conductive copper components and has optimized the material and the process on a standard printer. The material and manufacturing specialist produces components with 99.8 percent density of solid copper and conductivity of about 95 percent IACS (International Annealed Copper Standard). Around 85 percent IACS is customary in the market. “With this boost in quality, additive manufacturing of highly conductive copper components is now possible, worthwhile and cost-efficient in many industrial sectors,” emphasizes Tobias Caspari, Head of Heraeus Additive Manufacturing. His developers deliver reproducible high-quality components and are setting standards in spare parts procurement, which is reduced from several months to a few days.
Examples of applications include components in the areas of electric drives, inductive heating, thermal management and other applications that utilize the excellent electrical and thermal characteristics of copper. In conventional manufacturing processes, manufacturing tolerances are often too high to achieve reproducibility in particularly sensitive manufacturing processes – for example, in the case of products for sophisticated cooling elements or laser transmission. “We’ve solved this problem as well. We’re now working on further increasing the conductibility of micro-alloyed copper and applying our findings to other standard machines.” Customization is necessary because the machines from different manufacturers behave differently. The quality of the component is determined by the material, the process and the printing system.
The challenge for the material and process developer: Copper has high conductivity and ductility, but reflects the laser wavelength that is used in standard machines almost like a mirror. At the same time, the high thermal conductivity of copper causes quick dissipation of the coupled energy. This results in a very narrow process window. Conventional 3D printing of pure copper is impossible because of these characteristics. So far, one approach to solving this problem has consisted of using various copper alloys – in each case at the expense of conductivity and other characteristics like resistance to corrosion. Another approach to solving this problem has been to modify the manufacturing process, which involves compromises in the component’s quality. For example, the component will exhibit greater porosity if the laser beam only begins to melt the material but does not melt it completely. A third approach to solving this problem consists of using other laser sources. A commercial implementation of this approach does not exist yet.
At Formnext 2018, Heraeus will present its new development and show highly conductive 3D-printed copper components. The material and process specialist will show additional technological highlights that are relevant for the fields of mobility, electronics, robotics, hydraulics, medicine and aerospace. The focus will be on additive manufacturing with special materials from the set of amorphous metals, refractory metals, precious metals, and alloys for lightweight construction, such as Scalmalloy.