Efficient Use of Resources for Manufacturing Metal Components

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The 3D-Printing Lab for Metals and Structural Materials at Fraunhofer Institute for High-speed Dynamics, Ernst-Mach-Institute, EMI, in Freiburg, Germany, houses one of the largest commercially available 3D printers for metal currently in existence. Metal structures with dimensions of up to 40 centimetres can be additively manufactured using the selective laser melting technique. 3D printing offers completely new ways of designing components with highly complex shapes while optimising their weight. However, Fraunhofer researchers advocate that it is only by combining additive manufacturing and intelligent lightweight design that maximum resource efficiency in manufacturing can be achieved. Researchers in the 3D-Printing Lab have been investigating just how resource-efficient the manufacturing process is when manufacturing lightweight aluminium components based on the example of a wheel carrier. The focus was on energy and material consumption, manufacturing time and CO₂ emissions that arise during a small production run of twelve wheel carriers.

Reducing manufacturing costs for small-scale series production

The researchers used the numerical finite element method (FEM) to construct a wheel carrier with an optimised lightweight design that is adapted for the defined load scenarios and offers maximum performance. Due to their geometric complexity, structures produced in this way cannot be manufactured by conventional methods such as milling or turning. Using the numerically optimised version of the wheel carrier, fifteen percent less energy was required for the additive process than for the conventional design. Twelve kilowatt hours of electricity were needed for the conventional design compared to ten kilowatt hours for the numerically optimised design (in each case, the measured value refers to a series-manufactured component). Manufacturing time was cut by 14 percent and CO₂ emissions by 19 percent, while material consumption was reduced even more significantly, by 28 percent.

The results of the small-scale series production of the wheel carrier suggest that additive manufacturing can also be useful when a component does not have to be structurally optimised as such. "A heat exchanger and a tool mould, for example, do not have to be lightweight to improve their functionality. Nevertheless, it makes sense to design them with reduced weight and volume when manufacturing them additively, because this way you can bring down manufacturing costs," explains Klaus Hoschke, scientist and group leader at Fraunhofer EMI.