Numerical Investigation into the Effect of Different Parameters on the Geometrical Precision in the Laser-Based Powder Bed Fusion Process Chain
Round 1
Reviewer 1 Report
On behalf of applsci-778904: “Numerical investigation into the effect of different parameters on the geometrical precision in the laser-based powder bed fusion process chain”
- In LBPF, surrounding non-melted powder also helps with heat dissipation. This has apparently not been included in your study. Why?
- You seem to assume that each “layer element” reaches the melting temperature at the same time, neglecting the effect of scan strategy within layer and, consequently, ignoring the residual stress behaviour inside each element. Why?
- The part that you have proposed seems to be oriented in the workspace according to Figure 5, whit the largest horizontal surface being the last to be manufactured. Is this true? In that case, you have included several overhangs that would not be manufactured in a LBPF without additional support structures. Please discuss this fact.
- With no experimental data from actual manufactured parts, it is not possible to evaluate the accuracy and usefulness of your work. Why haven´t you included a final verification step?
You provide no description of the process. Not all LBFP melt the metal particles, some of them just sinterize the material and the temperature never reaches upo to the melting point. You must indicate the conditions of the process you are simulating, since there is no such thing as a “generic” LBFP, and particularities of processing parameters deeply affect the accuracy of simulation.
Author Response
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Reviewer 2 Report
In this article, the authors develop and demonstrate a simple and effective numerical model to explore the effects of LPBF process parameters on the geometrical precision of the final parts. The paper is very well written and the approach and numerical experiments are very well designed and presented. The approach presented is somewhat novel (there are may competing solutions, as the authors acknowledge in the literature review), but the exact contributions from the paper are clearly specified. This paper is unusually clear and well presented for similar works. The work is useful and the model fits what I expect from the process. In the future, I would like to see more physical experiments to verify the findings of this paper, but that is not necessary for an initial paper on the topic from this group.
In the present form, I think the paper is helpful and clear and provides a useful contribution to the field. After careful review, I do not have any major concerns or suggestions for improvement. Therefore, I recommend that the editor accept the paper for publication Applied Sciences in the current form.
Author Response
Please see attachment for the response to the comments of reviewer 2
Author Response File: Author Response.docx
Reviewer 3 Report
First of all a piece of advice: ANSYS is all time checking the use of licensed out of academic land. For this kind of work the license must be RESEARCH, if not…better to reduce ANSYS´s figures.
- Eliminate the systematic reference to ANSYS in the abstract and in many parts of the work, the real contribution must be knowledge. Try to express the features given by ANSYS in other approaches.
- Figures 10 and 13…are tey all necessary? Please define the model, after that we believe in ANSYS…go and aim at results.
- Heat treatment is key in residual stresses. Please discuss the calculations and real values obtained by Hole drilling technique and Diffraction XR.
- Plate removal can be done by hammer or by EDM. In both cases results could be different. Please comment that.
- State of the art: partial, some key references are missed: models are more advanced in laser polishing (Optics and Lasers in engineering 90, 72-80) or Laser cladding such as Optimal parameters for 5-axis laser cladding, Procedia Engineering 63, 45-52, there are few references to Yadroitsev such his key work Journal of Materials Processing Technology 210 (12), 1624-1631, and in addition Thermal model with phase change for process parameter determination in laser surface processing, Physics Procedia 5, 395-403
- Ref 20, 29 or 36..are overtaken by time, please replace. Only few references from metals or materials, or Applied science journals. Too many about JMPT.
Author Response
Please see attachment for the response to the comments of reviewer 3
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Regarding applsci-778904: “Numerical investigation into the effect of different parameters on the geometrical precision in the laser-based powder bed fusion process chain”
I truly appreciate your efforts. I am aware that you have truly revised conscientiously your work. The problem here is that, although I´m sure that you are rigorous in your approach, the provided example could not be possibly manufactured as you proposed. Applying such methodology to a design that could never be manufactured in the selected way means that your results could never be verified. This is just opposed to my notion of what science should be.
I am aware that the problem affects the core of your work, but my recommendation is that you should select a different part, which could help you to explain your approach while, at the same time, allow other researchers to verify the accuracy of your results.
Author Response
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Reviewer 3 Report
The only reference in which authors calculated the realibility of additive SLMed pieces is in MDPI, by Dr Coro Metals 2019, 9(9), 932; https://doi.org/10.3390/met9090932 based on a previous work en Advances in Mechanical Engineering. The author gives one step ahead of your approach, instead of evaluating the piece He or She evaluates the consequences in piece life. The idea is under consideration now by AAAI society, so it is obliged to address it in all additive works, instead for instance of ref 43 and 44
Author Response
Please see the attachment for the response to the reviewer's comments
Author Response File: Author Response.docx
