Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 May 6;16(9):3556.
doi: 10.3390/ma16093556.

Static and Dynamic Mechanical Behaviour of Hybrid-PBF-LB/M-Built and Hot Isostatic Pressed Lattice Structures

David Sommer  1 , Cemal Esen  2 , Ralf Hellmann  1
Affiliations

Static and Dynamic Mechanical Behaviour of Hybrid-PBF-LB/M-Built and Hot Isostatic Pressed Lattice Structures

David Sommer et al. Materials (Basel). .

Abstract

We report on a comprehensive study of the mechanical properties of maraging steel body-centred cubic lattice structures fabricated by a hybrid additive manufacturing technology that combines laser powder bed fusion with in situ high-speed milling. As the mechanical properties of additive manufactured components are inferior to, e.g., cast components, surface modifications can improve the mechanical behaviour. Different hybrid additive manufacturing technologies have been designed using additive and subtractive processes, improving process quality. Following this, mechanical testing is performed with respect to static tensile properties and dynamic stress, hardness, and porosity, comparing specimens manufactured by laser powder bed fusion only to those manufactured by the hybrid approach. In addition, the influence of different heat-treatment techniques on the mechanical behaviour of the lattice structures is investigated, namely solution and aging treatment as well as hot isostatic pressing. Thus, the influence of the superior surface quality due to the hybrid approach is evaluated, leading to, e.g., an offset of about 14-16% for the static testing of HIP lattice structures. Furthermore, the dynamic load behaviour can be improved with a finished surface, heading to a shift of the different zones of fatigue behaviour in the testing of hybrid-built specimens.

Keywords: fatigue behaviour; hot isostatic pressing; hybrid additive manufacturing; lattice structures.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Schematic illustration of the hybrid additive manufacturing unit.
Figure 2
Figure 2
Hybrid additive manufacturing unit, showing the build plate with the recoater and the milling spindle.
Figure 3
Figure 3
Two stage milling process with two different milling parts for the hybrid system. (a) PBF-LB/M process; (b) Roughing process; (c) Finishing process.
Figure 4
Figure 4
(a) Dimensions of the milling cutter, (b) milling of lattice structures.
Figure 5
Figure 5
Surfaces of milled specimens: (a) as-built, (b) SAT and (c) HIP.
Figure 6
Figure 6
Stress–strain curve of the as-built lattice structures.
Figure 7
Figure 7
SEM images of (a) PBF-LB/M-built surface and (b) high-speed milled surface.
Figure 8
Figure 8
Stress–strain diagram for the comparison of Hybrid PBF-LB/M- and PBF-LB/M-built specimens for SAT lattice structures.
Figure 9
Figure 9
Stress–strain diagram for the comparison of Hybrid PBF-LB/M- and PBF-LB/M-built specimens for HIP lattice structures.
Figure 10
Figure 10
Comparing the as-built, SAT and HIP states for (a) density and (b) hardness.
Figure 11
Figure 11
Microstructure of the (a) as-built, (b) SAT and (c) HIP specimens.
Figure 12
Figure 12
Wöhler diagram for the (a) PBF-LB/M-built and (b) hybrid-built specimens, each comparing the as-built, SAT and HIP states.
Figure 13
Figure 13
Crack analysis for (a) as-built (zone 1: endurance failure, zone 2: forced fracture, getting divided by dashed line), (b) SAT and (c) HIP specimens for the same applied load.
Figure 14
Figure 14
Wöhler diagram for the (a) As-built, (b) SAT and (c) HIP specimens, comparing machined and unmachined specimens.
See this image and copyright information in PMC

References

    1. de Pasquale G., Luceri F., Riccio M. Experimental Characterization of SLM and EBM Cubic Lattice Structures for Lightweight Applications. Exp. Mech. 2019;59:469–482. doi: 10.1007/s11340-019-00481-8. - DOI
    1. Tao W., Leu M.C. Design of lattice structure for additive manufacturing; Proceedings of the International Symposium on Flexible Automation; Cleveland, OH, USA. 1–3 August 2016; pp. 325–332. - DOI
    1. Xiao Z., Yang Y., Xiao R., Bai Y., Song C., Wang D. Evaluation of topology-optimized lattice structures manufactured via selective laser melting. Mater. Des. 2018;143:27–37. doi: 10.1016/j.matdes.2018.01.023. - DOI
    1. Zhou H., Zhang X., Zeng H., Yang H., Lei H., Li X., Wang Y. Lightweight structure of a phase-change thermal controller based on lattice cells manufactured by SLM. Chin. J. Aeronaut. 2019;32:1727–1732. doi: 10.1016/j.cja.2018.08.017. - DOI
    1. Maskery I., Hussey A., Panesar A., Aremu A., Tuck C., Ashcroft I., Hague R. An investigation into reinforced and functionally graded lattice structures. J. Cell. Plast. 2017;53:151–165. doi: 10.1177/0021955X16639035. - DOI

LinkOut - more resources