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

Although the parts in this study and the literature • Highlighted the impact of process variables,
used optimized process parameters to achieve highly including part orientation, argon flow, supports,
dense, defect-free parts, it is possible that differences in and post-processing
the microstructure, such as finer or coarser grains or • Identified limitations in surface quality inherent
the presence of different phases, could lead to changes to LPBF technology, suggesting potential
in hardness. These factors influence the mechanical improvements through optimized process
properties of materials, including hardness, and may parameters or advanced post-processing methods
explain the higher hardness in our study compared to such as vibratory tumbling or electrochemical
literature values. 50,51 polishing
Thus, the higher hardness observed in this study is • Findings emphasize the importance of refining
not solely due to differences in powder characteristics process parameters and post-processing
or densification but is more likely attributable to techniques to achieve a smoother surface finish,
microstructural differences, including grain size and which is critical for improving esthetic quality
precipitates or other phases. Further studies focusing on and tribological performance.
the microstructure characterization in both this study • Tribological investigations:
and the literature would provide a more comprehensive • Surface roughness is critical in tribological
understanding of how these factors contribute to variations performance, influencing friction and wear
in hardness and other mechanical properties. behavior
• The tribological behavior of the component
4. Conclusions showed that surface roughness values directly
correlate with friction and wear performance.
This study explored a bicycle crank’s TO and AM in Further optimization of the surface texture
AlSi10Mg using LPBF. The research successfully developed through post-processing may enhance the
a lightweight and structurally optimized component by component’s durability and functionality in real-
integrating advanced design strategies such as lattice world applications.
structures. Rigorous testing and analysis validated the • Dimensional analysis:
prototype’s compliance with standards, manufacturability, • Demonstrated variability in dimensional
and mechanical performance. The findings underscore the accuracy, with deviations of 0.66 ± 0.39 mm for
potential of TO and LPBF for creating high-performance, lengths and 0.12 ± 0.05 mm for circle radii
lightweight components while identifying areas for further • Suggested improvements through additional
improvement. Key conclusions drawn from this study are supports, changes in part orientation, or adjustments
as follows: to the geometry for enhanced manufacturability.
• Component achievement: • Material and powder characteristics:
• Successfully designed and manufactured a • The narrow particle size distribution of AlSi10Mg
topology-optimized bicycle crank in AlSi10Mg powders facilitated consistent production results
using LPBF despite a 40% satellite particle presence.
• The single-part component complies with ISO • Considerations for future studies:
14781 and was validated through static testing • Conduct more detailed roughness studies,
• A lightweight design of 458 g was achieved by focusing on stair-stepping effects
incorporating lattice structures into the topology- • Define dimensional tolerances for prototypes to
optimized component enhance validation accuracy
• Despite the production process’s complexity, • Investigate the effects of particle size distribution
careful lattice cell selection ensured the successful and satellite particle percentages on the
fabrication of a functional prototype. component’s mechanical and surface properties
• Validation and testing: • Explore scalability and economic feasibility for
• Microstructure analysis: potential industrial applications
• Revealed elongated melt pools aligned with • Examine the tribological performance of the
the scan direction, consistent with LPBF component in greater detail, including wear
technology resistance and friction in operational conditions
• Confirmed the absence of excessive porosity, • Further, optimize post-processing methods
ensuring manufacturing integrity. to enhance surface quality and tribological
• Surface roughness analysis: performance.

Volume 4 Issue 1 (2025) 12 doi: 10.36922/MSAM025040003