Geometry Assurance of Laser Processed Metal Components
Doctoral thesis, 2021
While great progress has been made in understanding their process capabilities, shortfalls remain in the area of geometric quality. Specifically, addressing the effect of local heating and local melting on geometric variation is scarce due to the novelty of the aforementioned manufacturing processes. As a result, the methods and tools in practice today may not be readily applicable to analyzing and minimizing the effect of local heating and local melting on geometric vari-ation. Thus, this thesis aims at developing knowledge to provide insights into the effect of the aforementioned manufacturing processes on geometric variation and, thereby, assist in establishing methods and tools for the geometry assurance process.
To this end, literature studies were performed to map the significant factors influencing geometric variation and a robust design framework was established as the first step. The focus was then focused towards analysing a set of factors that could be optimized in the early design stages. Specific to the selective laser heat treatment of boron steels, the effect of factors such as the laser heat treat-ment grid pattern dimension, laser heat treatment grid pattern position, and laser heat treatment scanning path sequence on geometric variation were analysed. Meanwhile, in the selective laser melting of 316L stainless steel powder, the effect of factors such as particle size distribution and powder layer thickness on geometric variation were analysed.
The results highlight the significance of considering the effect of the specified set of factors on geometric variation in the early product development stages and offer solutions to minimize the effect on geometric variation. Moreover, simulation techniques are presented that enable accurate decision making and demonstrate integration into the virtual product development setup. In summary, this thesis demonstrates the application of a robust design approach and the significance of considering geometry assurance in the product development process of laser processed metal components.
selective laser melting
selective laser heat treatment
Vaishak Ramesh Sagar
Chalmers, Industrial and Materials Science, Product Development
Geometrical Variation from Selective Laser Heat Treatment of Boron Steels
Procedia CIRP,; Vol. Volume 75(2018)p. 409-414
Paper in proceeding
Influence of Selective Laser Heat Treatment Pattern Position on Geometrical Variation
Journal of Manufacturing Science and Engineering, Transactions of the ASME,; Vol. 141(2019)
Effect of selective laser heat treatment on geometrical variation in boron steel components: An experimental investigation
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture,; Vol. 235(2021)p. 54-64
A Robust Design Perspective on Factors Influencing Geometric Quality in Metal Additive Manufacturing
Journal of Manufacturing Science and Engineering, Transactions of the ASME,; Vol. 143(2021)
A Simulation Study on the Effect of Particle Size Distribution on the Printed Geometry in Selective laser Melting
A Simulation Study on the Effect of Layer Thickness Variation on the Printed Geometry in Selective Laser Melting
For novel laser-based manufacturing processes such as laser heat treatment of sheet metals, laser-assisted metal additive manufacturing, knowledge on geometric variation sources is limited. Also, the methods and tools in practice today may not be readily applicable to support in analyzing and minimizing the effect of variation.
The research presented in this thesis has focused on developing knowledge to provide insights into the effect of the aforementioned manufacturing processes on geometric variation and, thereby, assist in establishing methods and tools for the geometry assurance process. A set of geometric variation contributors are identified and solutions to minimize the effect on geometric variation are prescribed. Moreover, simulation methods are presented that enable accurate decision-making and demonstrate integration into the virtual product development setup. In summary, this thesis demonstrates the significance of considering geometry assurance in the product development process of laser processed metal components.
Manufacturing, Surface and Joining Technology
Areas of Advance
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4962
Chalmers University of Technology
Virtual Development Laboratory (VDL), Hörsalsvägen 7A, Gothenburg, Sweden
Opponent: Professor Nader Asnafi, Örebro University, Örebro, Sweden