Sinclair et al. - Additive Manufacturing 2020 - Supplementary Material - In situ radiographic and ex situ tomographic analysis of pore interactions during multilayer builds in laser powder bed fusion

Oct 28, 2026

Upload by acoobca

Supplementary material describing how porosity percentage was calculated from µCT data for laser powder bed fusion multilayer builds. The method measures track volume above the substrate with pores filled, estimates additional remelting volume using a boundary box and keyhole depth, and combines these to derive total track volume. The porosity volume fraction is then computed as a percentage, with a reported 2–6% error from a triangular substrate section model. Supplementary tables, figures, and multiple sample/layer videos document energy density inputs and evolving morphology, keyhole behavior, and fusion/undulation features.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages47

Reading Time1 h 58 min

AccessFree to download

Porosity Percentage Calculation

Supplementary Table 1: Linear Energy Density Values

Supplementary Figures 1-3

Supplementary Videos 1-11

References

[eprints@whiterose.ac.uk](eprints@whiterose.ac.uk)[ ](eprints@whiterose.ac.uk)[https://eprints.whiterose.ac.uk](https://eprints.whiterose.ac.uk) Universities of Leeds, Sheffield and York Deposited via The University of Leeds. White Rose Research Online URL for this paper: [https://eprints.whiterose.ac.uk/id/eprint/164231/](https://eprints.whiterose.ac.uk/id/eprint/164231/) [Version: Accepted Version](Version: Accepted Version) Article: Sinclair, L, Leung, CLA, Marussi, S et al. (2020) In situ radiographic and ex situ tomographic analysis of pore interactions during multilayer builds in laser powder bed fusion. Additive Manufacturing, 36. 101512. ISSN: 2214-8604 [https://doi.org/10.1016/j.addma.2020.101512](https://doi.org/10.1016/j.addma.2020.101512) © 2020, Elsevier B.V.. This manuscript version is made available under the CC-BY-NC-ND 4.0 license [http://creativecommons.org/l](http://creativecommons.org/l)icenses/by-nc-nd/4.0/. Reuse This article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) licence. This licence only allows you to download this work and share it with others as long as you credit the authors, but you can’t change the article in any way or use it commercially. More information and the full terms of the licence here: [https://creativecommons.org/licenses/](https://creativecommons.org/licenses/) Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [eprints@whiterose.ac.uk](eprints@whiterose.ac.uk) including the URL of the record and the reason for the withdrawal request. Supplementary Information Porosity Percentage Calculation The percentage of porosity in the samples was calculated using the µCT data. The total volume of the track above the substrate, with all pores filled, was measured. It is not possible to determine the volume of remelting into the substrate from the µCT scan, however a basic estimation has been calculated using a boundary box at the widest parts of the track, and a depth into the substrate at the deepest keyhole for each condition. This volume plus the track volume (above the substrate) were used as the estimation for total track volume. The volume porosity was then calculated as a percentage of this. This is a slight overestimation of total track volume, and thus underestimation of porosity percentage. The error was calculated by estimating a triangular section through the substrate, using the width of the boundary box and depth of the keyhole pores. This gave an error of 2 – 6 % for the porosity percentage calculation. Supplementary Table 1 Linear energy density values from previous work and the present study. Hatch spacing has not been included in this calculation (LED = P/vt) for direct comparison to the energy densities presented here. | Laser Power, P
(W) | Scan Speed, v
(mm s-1) | Powder layer thickness, t (mm) | LED (J mm-2) | Reference | | --- | --- | --- | --- | --- | | 175 – 400 | 500 – 1100 | 0.03 | 12 | [1] | | 275 | 750 | 0.05 | 7.3 | [2] | | 400 | 50 – 125 | 0.25 | 13-32 | [3] | | 100 | 560 | 0.04 | 4.5 | [4] | | 100 – 400 | 400 – 1600 | 0.05 | 5-10 | [5] | | 42 | 200 | 0.03 | 7 | [6] | | 200 | 200 – 400 | 0.1 | 5 – 10 (nominal)
3 – 9 (adjusted) | Present
work | Supplementary Figure 1 : Graphs showing the change in layer 5 deposited powder thickness in (a) Sample A, (b) Sample C, and (c) Sample D. Supplementary Figure 2: (a) Background corrected but unedited radiograph of Sample A layer 3 final morphology, with red highlighted region correlating to (b – d) in Figure 3. (b) Background, GC plate surface, and excess powder removed from the image to highlight surface shape. A section on this image was taken for Figure 3c. Supplementary Figure 3: SEM image of Sample D, showing partially melted powder particles adhered to the track surface. Supplementary Video 1: Sample A, Layer 1, showing ca. 50 µm

FAQs

What source of uncertainty is quantified for the porosity calculation?

Error is evaluated by estimating a triangular section through the substrate using the boundary box width and keyhole pore depth, resulting in an error of about 2–6% for the porosity percentage calculation.

Oct 28, 2026

Upload by acoobca