Design for Additive Manufacturing and for Machining in the Automotive Field

High cost, unpredictable defects and out-of-tolerance rejections in final parts are preventing the complete deployment of Laser-based Powder Bed Fusion (LPBF) on an industrial scale. Repeatability, speed and right-first-time manufacturing require synergistic design approaches. In addition, post-build finishing operations of LPBF parts are the object of increasing attention to avoid the risk of bottlenecks in the machining step. An aluminum component for automotive application was redesigned through topology optimization and Design for Additive Manufacturing. Simulation of the build process allowed to choose the orientation and the support location for potential lowest deformation and residual stresses. Design for Finishing was adopted in order to facilitate the machining operations after additive construction. The optical dimensional check proved a good correspondence with the tolerances predicted by process simulation and confirmed part acceptability. A cost and time comparison versus CNC alone attested to the convenience of LPBF unless single parts had to be produced.

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GEOMETRICAL BENCHMARKING OF LASER POWDER BED FUSION SYSTEMS BASED ON DESIGNER NEEDS

Proceedings of the Design Society ◽

10.1017/pds.2021.427 ◽

2021 ◽

Vol 1 ◽

pp. 1657-1666

Author(s):

Joaquin Montero ◽

Sebastian Weber ◽

Christoph Petroll ◽

Stefan Brenner ◽

Matthias Bleckmann ◽

...

Keyword(s):

Additive Manufacturing ◽

Use Case ◽

Powder Bed Fusion ◽

Design For Additive Manufacturing ◽

Laser Powder Bed Fusion ◽

Measuring Systems ◽

Powder Bed ◽

Geometric Dimensioning And Tolerancing ◽

Uncertainty Map ◽

New System

AbstractCommercially available metal Laser Powder Bed Fusion (L-PBF) systems are steadily evolving. Thus, design limitations narrow and the diversity of achievable geometries widens. This progress leads researchers to create innovative benchmarks to understand the new system capabilities. Thereby, designers can update their knowledge base in design for additive manufacturing (DfAM). To date, there are plenty of geometrical benchmarks that seek to develop generic test artefacts. Still, they are often complex to measure, and the information they deliver may not be relevant to some designers. This article proposes a geometrical benchmarking approach for metal L-PBF systems based on the designer needs. Furthermore, Geometric Dimensioning and Tolerancing (GD&T) characteristics enhance the approach. A practical use-case is presented, consisting of developing, manufacturing, and measuring a meaningful and straightforward geometric test artefact. Moreover, optical measuring systems are used to create a tailored uncertainty map for benchmarking two different L-PBF systems.

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Numerical Prediction of Residual Deformation and Failure for Powder Bed Fusion Additive Manufacturing of Metal Parts

Journal of Mechanics ◽

10.1017/jmech.2020.30 ◽

2020 ◽

Vol 36 (5) ◽

pp. 623-636

Author(s):

D.D. Lyu ◽

W. Hu ◽

B. Ren ◽

X.F. Pan ◽

C. T. Wu

Keyword(s):

Additive Manufacturing ◽

Process Simulation ◽

Residual Deformation ◽

Numerical Approach ◽

Small Scale ◽

Powder Bed Fusion ◽

Failure Characteristics ◽

Deformation And Failure ◽

Powder Bed ◽

Inherent Strain Method

ABSTRACTResidual deformation and failure are two critical issues in powder bed fusion (PBF) additive manufacturing (AM) of metal products. Residual deformation caused by the non-uniform residual stress distribution dramatically affects the quality of AM product and can result in catastrophic failure in operation. Therefore, the development of an effective numerical approach to predict residual deformation and failure characteristics of AM product is always a major concern in industrial applications.In this paper, a numerical approach in predicting residual distortion, stress and failure in AM products is presented. The conventional inherent strain method used in welding process is modified to consider the specific characteristic of AM process, such as the influences of reheating and scanning pattern. This approach consists of three simulation steps including a detailed process simulation in small-scale, a onetime static mechanical finite element analysis in part-scale, and a material failure analysis. First, the inherent strains are calculated from a thermo-mechanical process simulation in small-scale, which considers AM process parameters, such as laser power, scanning speed and path. The physical state in deposited materials including powder, liquid and solid states are taken into account in the simulation by specifying the solidus and liquidus temperature and corresponding material properties. Then the inherent strains are applied layer by layer to the part-scale simulation, where the residual distortion and stress can be predicted efficiently. Finally, a Lagrange particle method is utilized to study the failure characteristics of AM products. Numerical examples are studied to investigate the effectiveness and applicability of present approach.

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RE-DESIGN OF ADDITIVE MANUFACTURED SPARE PARTS BASED ON FEATURES CLASSIFICATION

Proceedings of the Design Society: DESIGN Conference ◽

10.1017/dsd.2020.168 ◽

2020 ◽

Vol 1 ◽

pp. 1007-1016

Author(s):

J. Montero ◽

S. Weber ◽

M. Bleckmann ◽

K. Paetzold

Keyword(s):

Additive Manufacturing ◽

Case Studies ◽

Spare Parts ◽

Design Approach ◽

Legacy Systems ◽

Powder Bed Fusion ◽

Design For Additive Manufacturing ◽

Laser Powder Bed Fusion ◽

Powder Bed

AbstractAdditive Manufacturing is doing its first steps in the production of spare parts. Usually the spares belong to legacy systems, and the tooling to produce them is no longer available. Re-designing spares that are designed for a previous industry mindset can be sometimes challenging. In this study a rather classic design approach is compared to a functional driven approach. Four case studies from different clients are reported, remarking the benefits and drawbacks of using design for additive manufacturing practices in Laser Powder Bed Fusion.

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Design for Additive Manufacturing of a Topology Optimized Brake Caliper Through CAD-Platform-Based Systematic Approach

Lecture Notes in Mechanical Engineering - Advances on Mechanics, Design Engineering and Manufacturing III ◽

10.1007/978-3-030-70566-4_16 ◽

2021 ◽

pp. 92-97

Author(s):

Enrico Dalpadulo ◽

Fabio Pini ◽

Francesco Leali

Keyword(s):

Titanium Alloy ◽

Additive Manufacturing ◽

Thermal Behavior ◽

Optimization Process ◽

Powder Bed Fusion ◽

Design For Additive Manufacturing ◽

Powder Bed ◽

Formula Sae ◽

Ti6al4v Titanium Alloy ◽

Geometrical Features

AbstractTo implement the CAD platform-based approach of Design for Additive Manufacturing (DfAM) and validate it in a real case, an entire design optimization process of a Formula SAE front brake caliper has been performed, to be printed by Powder Bed Fusion (PBF) process. The DfAM consists in the use of a Ti6Al4V titanium alloy to better resist at high temperatures and a topology optimized shape allowed by the technology to save weight despite the density increase. Structural and thermal behavior has been discussed. DfAM process-specific techniques have been implemented for internal geometrical features and optimized shapes. The design for additive workflow is presented and finally the exploited design approach based on a CAD platform is synthesized.

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PARAMETERS ON SUPPORT STRUCTURE DESIGN FOR METAL ADDITIVE MANUFACTURING

Proceedings of the Design Society: DESIGN Conference ◽

10.1017/dsd.2020.14 ◽

2020 ◽

Vol 1 ◽

pp. 1145-1154

Author(s):

S. Weber ◽

J. Montero ◽

M. Bleckmann ◽

K. Paetzold

Keyword(s):

Additive Manufacturing ◽

Design Of Experiments ◽

Structure Design ◽

Design Parameters ◽

Powder Bed Fusion ◽

Design For Additive Manufacturing ◽

Laser Powder Bed Fusion ◽

Support Structure ◽

Powder Bed ◽

Metal Additive

AbstractThe topic of support structure design in the Design for Additive Manufacturing (DfAM) field is not addressed with the same relevance as the topic of part design. Therefore, this contribution investigates parameters for both the manufacturing and support structure design for the Laser Powder Bed Fusion (L-PBF) process. Matrices for cause-effect-relations of manufacturing and design parameters on build properties as well as correlations of them are presented. Based on these, recommendations for actions for experimental procedures are derived following the Design of Experiments method.

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