New Ways to Reduce Weight and Costs in Metal 3D Printing

Metal laser melting, or metal 3D printing, can be used to manufacture complex and efficient lightweight structures that are particularly beneficial in the aerospace and motorsport sectors where every gram counts. Last year, we decided to start using the Siemens NX software package to improve our process chain, from design and construction to modifications using machining techniques. As a result, we are now able to produce even more efficient components thanks to the weight and cost reductions enabled by the modules for finite element method (FEM) calculations and basic shape (topology) optimization that are built into the software. Special features for topology optimization and FEM calculations enable us to design optimal components by analyzing not only the material being employed and the laser-melted test pieces, but the forces subsequently exerted on the component as well.

The software can be used to reproduce the load paths and internal stresses that later act on the component. The ambient temperature can also be taken into account. Using this data, the program identifies the areas in which the amount of material can be reduced. The simulated results provide detailed information on the stresses and strains exerted within the optimized component. While the level of stress is high in the areas highlighted in red, the green and blue areas depict regions where there is a lower amount of stress. This information enables designers to evaluate the topology optimization results in terms of functionality and durability, allowing weight to be reduced to the minimum amount possible without there being a detrimental effect on the component properties. In most cases, a safety factor is included in the calculation so that the completed part can withstand an even greater load than stated in the specification.

The finite element method not only results in lightweight components “losing” weight, but also optimizes their design. Designers can use topology optimization to calculate the most efficient basic shape of a component, all while taking into account the mechanical loads to which it will later be subjected. Besides conserving materials, optimizing a component’s design in advance means that fewer modifications will be required once it is actually produced. For example, there would be less of a need to remove support structures, apply surface treatments or perform any reworking using machining processes. A further advantage of this analysis is the ability to use different materials. The calculations enable designers to ascertain which material would be most suitable for the way in which the component is to be subsequently used. This not only saves additional time and materials, but further reduces the need for reworking.

For shops such as ours that are committed to improving their procedures and the complete process chain, including optical and tactile measuring and non-destructive testing in accordance with NADCAP, component quality is crucial, especially in applications where safety is of vital importance or certification is required. This is why it is important to also assess the dynamic strength of various metals by performing laboratory fatigue testing in-house.