How defects depend on geometry and scanning strategy in additively manufactured AlSi10Mg

Englert, Lukas; Czink, Steffen; Dietrich, Stefan; Schulze, Volker

doi:10.1016/j.jmatprotec.2021.117331

Cited by 11 publications

(3 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, a smaller construction angle leads to an increase in global porosity due to the thinner contour area at the downskin surface of the sample. Due to the insulating effect of the surrounding powder, heat buildup occurs in the PBF-LB process of samples with a smaller construction angle, which can additionally promote the formation of hydrogen pores [51,52]. However, the average sphericity of the pores is quite high, suggesting that the majority of pores have a spherical shape, which supports the assumption of isotropic elastic material behavior.…”

Section: Topology Optimization Methodsmentioning

confidence: 76%

Process-Specific Topology Optimization Method Based on Laser-Based Additive Manufacturing of AlSi10Mg Components: Material Characterization and Evaluation

Czink

Holoch²,

Renz³

et al. 2023

Processes

Self Cite

View full text Add to dashboard Cite

In the laser powder bed fusion process (PBF-LB), components are built up incrementally by locally melting metal powder with a laser beam. This process leads to inhomogeneous material properties of the manufactured components. By integrating these specific material properties into a topology optimization algorithm, product developers can be supported in the early phases of the product development process, such as design finding. For this purpose, a topology optimization method was developed, which takes the inhomogeneous material properties of components fabricated in the PBF-LB process into account. The complex pore architecture in PBF-LB components was studied with micro-computed tomography (µCT). Thereby, three characteristic regions of different porosity were identified and analyzed. The effective stiffness in each of these regions was determined by means of resonant ultrasonic spectroscopy (RUS) as well as finite element analysis. Afterward, the effective stiffness is iteratively considered in the developed topology optimization method. The resulting design proposals of two optimization cases were analyzed and compared to design proposals derived from a standard topology optimization. To evaluate the developed topology optimization method, the derived design proposals were additionally manufactured in the PBF-LB process, and the characteristic pore architecture was analyzed by means of µCT.

show abstract

Section: Topology Optimization Methodsmentioning

confidence: 76%

Process-Specific Topology Optimization Method Based on Laser-Based Additive Manufacturing of AlSi10Mg Components: Material Characterization and Evaluation

Czink

Holoch²,

Renz³

et al. 2023

Processes

Self Cite

View full text Add to dashboard Cite

show abstract

“…The specimens were manufactured using a laser power of 230 W, a scan speed of 1000 mm s −1 , a layer height of 30 µm and a scan line spacing of 150 µm. The parameters used were selected based on previous research (see [11]) and kept constant to only investigate the influence of the scanning strategy on pore formation. The specimen geometry used is shown in Figure 1.…”

Section: Additive Manufacturing and Specimen Geometrymentioning

confidence: 99%

“…The development of new scan strategies could be further aided through the free modifiability of the G-code in the intermediate representation, similar to the strategies developed by Yeung et al [15]. As shown in [11], the formation of pores at overhangs is dependent on the size of the overhanging structure as well as the process parameters. These locations can be found in the intermediate representation, so that the laser power or scan speed could be adapted to be optimal for these structures.…”

Section: Design Guidelines For Scanning Strategiesmentioning

confidence: 99%

Concentric Scanning Strategies for Laser Powder Bed Fusion: Porosity Distribution in Practical Geometries

2022

Self Cite

View full text Add to dashboard Cite

Besides the optimisation of process parameters such as laser power or scan speed, the choice of the scan path represents a possibility to optimise the laser powder bed fusion process even further. The usual hatching strategy creates a homogeneous microstructure but makes it necessary to switch the laser off and on after each scan vector, which can slow down the fabrication. Moreover, the end of each scan vector is a location susceptible to the creation of keyhole pores. In this work, these disadvantages were meant to be avoided by using scan strategies that consist of longer paths and thus less end of track points. To this end, an open-source tool to tailor the LPBF G-code to geometric part features and advanced path configurations was developed and embedded into a co-visualization platform. With this tool, specimens built with four different types of paths were fabricated and the effect of these alternative scan strategies on pore distributions and path neighbourhood was investigated using micro-computed tomography. In the examined example geometry, a spiral scan pattern reduced the distance the laser had to jump between scanning by 78%. However, with the alternative path patterns, the defect architecture was strongly dependant on the part geometry and increased the overall porosity to 0.42%. Respective alleviation approaches are therefore necessary and are discussed in the remainder of this work.

show abstract

Concept for In-process Measurement of Residual Stress in AM Processes by Analysis of Structure-Borne Sound

Groenewold

Stamer

Lanza

2023

Lecture Notes in Production Engineering

View full text Add to dashboard Cite

How defects depend on geometry and scanning strategy in additively manufactured AlSi10Mg

Cited by 11 publications

References 28 publications

Process-Specific Topology Optimization Method Based on Laser-Based Additive Manufacturing of AlSi10Mg Components: Material Characterization and Evaluation

Process-Specific Topology Optimization Method Based on Laser-Based Additive Manufacturing of AlSi10Mg Components: Material Characterization and Evaluation

Concentric Scanning Strategies for Laser Powder Bed Fusion: Porosity Distribution in Practical Geometries

Concept for In-process Measurement of Residual Stress in AM Processes by Analysis of Structure-Borne Sound

Contact Info

Product

Resources

About