The inverse heat placement problem in metal additive manufacturing: Why a rational approach is needed for powder bed fusion

Published

May 15, 2024

Author(s)

John Billingham, Ho Yeung, Dragos Axinte, Zhirong Liao, Jason Fox

Abstract

Powder bed fusion (PBF) uses an energy beam to scan a powder bed surface, heat it locally and consolidate the material to form a part. The choice of energy beam paths is typically based on user experience. Simple beam path strategies (e.g., raster or spiral) are used and the thermal field analysed post hoc. We refer to this approach as solving the direct problem, which involves many modelling and experimental iterations until a close to satisfactory, but not optimal, thermal field is achieved. In contrast, we propose a rational approach, solving an inverse problem to control heat placement, which we illustrate using laser beam PBF. Starting from the desired thermal field to be induced in the powder bed, we show how to formulate and solve the Inverse Heat Placement Problem (IHPP) so that a set of time-varying beam parameters (path, scan speed, energy delivered) is obtained in a single iteration. Solving the IHPP takes the craftsmanship out of beam path planning and puts it on a sound scientific and mathematical basis. This will enable a step change in the quality and complexity of customised macro-, meso- and microscale properties of PBF built parts.

Citation

Journal of Materials Processing Technology

Volume

329

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.jmatprotec.2024.118447

Local Download

Keywords

powder bed fusion, thermal field, inverse problem

Citation

Billingham, J. , Yeung, H. , Axinte, D. , Liao, Z. and Fox, J. (2024), The inverse heat placement problem in metal additive manufacturing: Why a rational approach is needed for powder bed fusion, Journal of Materials Processing Technology, [online], https://doi.org/10.1016/j.jmatprotec.2024.118447, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957245 (Accessed February 6, 2025)