# Design for Additive Manufacturing and for Machining in the Automotive Field
## 3 Results
### Industrialization and Process Simulation  
By analyzing the stock part in Materialise Magics, two possible build orientations were identified, the support structures were designed for both, and the two models were then exported to Simufact Additive. The two selected orientations correspond to two conditions that minimize the volume of the supports and optimize the surface finish by avoiding surfaces that are nearly parallel to the build platform. The displacements and stresses predicted by process simulation are illustrated in Figure 2. They result from the combined action of thermal and mechanical loads [31]. In both orientations, the part is expected to experience a maximum displacement of 0.6 mm. However, if the Bracket 1 orientation is considered, the areas exposed to the maximum displacement are more extended. Moreover, in this orientation, the areas subjected to Von Mises stress values between 216 and 243 MPa (which represent maximum values for both orientations, thus approaching the yield limit of 270 MPa) are more significant. As a consequence, the orientation according to Bracket 2 was preferred.  
Figure 2: (**a**) Displacement (in mm) and (**b**) Von Mises stress (in MPa) distributions for the two relative orientations, Bracket 1 and Bracket 2, under exam. The orientation of the parts can be identified by the coordinate system at the bottom of the figure.  
Figure 1d shows the result of the final industrialization step in the chosen orientation, and Figure 1e shows the part built by LPBF after support removal and shot peening. If an SLM 280 machine is considered, the build table can host up to 12 brackets in the chosen orientation, together with three tensile specimens. Table 2 reports the job details under the former hypothesis.  
### Industrialization and Process Simulation  
In order to facilitate the machining operations, a special clamping system was developed and machined out of an aluminum AA5083 block. The stock model was held by means of its three appendices that were subsequently milled out. This allowed to define a straightforward clamping method in the machine tool and hence significantly compress the cycle time.  
As far as time is concerned, programming the CNC machining process both for the clamping equipment and for the workpiece required about 3 h, while machining itself required 2.5 h for the clamping system and 20 min for each workpiece. Figure 1f presents the final component after machining.  
Figure 3a shows the results of the dimensional control of the component still connected to the platform. It can be observed that dimensional errors range from \(-0.6\) to 0.5 mm. Grey zones are due to support structures that hide such areas from the optical scan [32]. Figure 3b shows the dimensional deviation of the finished part as compared to the CAD file. Figure 3c presents a histogram of the distribution of geometrical deviation. All the tolerance constraints were fulfilled on the finished part since the highest deviation was 0.34 mm, whereas the average deviation was as low as 0.065 mm. Interestingly, the maximum deviation measured on relevant surfaces, where the part is assembled with the nearby components, was just 0.19 mm.