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Materials Science in Additive Manufacturing Topology optimization of an aluminum bicycle pedal
crank using laser powder bed fusion

geometric versatility, customization potential, generative packing density – Van der Waals forces, particle radius,
design, and waste minimization. These attributes are and friction influence powder flowability. Smaller particles
5,6
pivotal across environmental, social, and economic with increased surface areas encounter augmented Van der
dimensions. 3,7 Waals forces and friction, impeding fluidity during layer
formation. Non-spherical shapes further augment the
Even with this, AM has limitations. It has not fulfilled 17-21
all prognosticated expectations despite being integrated surface area, adversely affecting flowability.
into the big data revolution. Compared to traditional AM technologies, such as LPBF, provide the flexibility
manufacturing techniques, challenges include mass to fabricate complex geometries and intricate internal
production scalability, size constraints, surface finishing features. By integrating Design for AM (DfAM), the design
imperfections, and the costs associated with raw materials, process can be optimized to leverage these capabilities
equipment, and initial capital. 8,9 fully, enabling the production of lightweight, highly
functional parts. 22-24 Topology optimization (TO) is used
Various AM technologies have been broadly adopted,
including fused filament fabrication, powder bed fusion in the DfAM approach, and it is a numerical approach
(PBF), stereolithography, selective laser sintering, and that identifies the optimal material distribution within a
digital light processing. 10,11 The selection among these given design space to achieve the desired functionality,
technologies is predicated on the desired functional, enhancing performance while minimizing material
usage.
The TO approach algorithmically determines
25-27
esthetic, and mechanical outcomes alongside financial the most structurally efficient design within a defined
considerations. Critical factors include part volume, layer space and under given constraints, resulting in organic,
12
volume, material deposition rate, and the balance between optimized shapes that use material only where necessary
material flexibility and mechanical requirements. AM 23,28,29
materials span polymers, metals, ceramics, and composites for structural integrity.
in diverse forms such as liquid, wire, powder, or sheet. 9,12,13 The integration of TO (and DfAM) in AM enhances
components’ structural performance and material
AM furnishes extensive modeling capabilities through
various design instruments that enable engineers and efficiency and plays a significant role in improving the
sustainability of manufacturing processes. TO reduces
designers to forecast mechanical responses and economic material waste, optimizes distribution within a given design
14
viability and automate part manufacturing processes. space, and ensures that only the necessary material is used
Among these, PBF systems, capable of utilizing either for structural integrity. This reduces both the material
electron beam or laser energy sources, offer exceptional consumption and the overall weight of the part, contributing
versatility. This article focuses on laser PBF (LPBF), an directly to sustainability. TO and AM technologies such
AM technology classified by ISO/ASTM. LPBF employs as LPBF contribute to energy efficiency. 30,31 The ability to
concentrated thermal energy from a laser to fuse materials, fabricate complex geometries that would be impossible or
depositing them layer by layer. 10
highly inefficient to produce using traditional subtractive
The LPBF process is initiated with a 3D computer- manufacturing methods allows for more efficient use of
aided design (CAD) model and machine programming, resources. By reducing material usage and minimizing
encompassing material loading, thermal heating, and waste during the manufacturing process, TO and AM
environmental setup (either vacuum or protective gas). provide an effective strategy for lowering the environmental
A recoater deposits a powder layer onto a construction impact of industrial production. 3,23
plate, followed by selective laser melting of the powder Previous studies, such as those by Mata et al. and
32
according to predetermined parameters. The construction Oliveira et al., have explored the successful integration
24
plate descends for each layer, replicating the process until of DfAM and TO in designing various components,
the component is complete. Post-processing involves showcasing how these approaches enable the creation
component removal, heat treatment, and finishing to of highly efficient, lightweight structures. Mata et al.
achieve desired performance standards. 1 optimized a metal door-handle design using nTopology
Raw material characteristics are vital in the LPBF and AM, focusing on lattice structures and generative
process, determining the final component’s mechanical design to reduce weight and enhance mechanical
and physical properties. Spherical powders, produced properties. Similarly, Oliveira et al. applied DfAM and TO
through gas atomization, are preferred for their enhanced to an office stapler, leveraging MEX technology for mass
fluidity during deposition, contributing to reduced reduction without compromising the part’s mechanical
porosity and satisfactory surface quality. 15,16 The spherical integrity. These studies illustrate the effectiveness of DfAM
geometry aids in stable molten pool formation and elevated and TO in producing lightweight, efficient structures, a

Volume 4 Issue 1 (2025) 2 doi: 10.36922/MSAM025040003