A Review on Modelling and Simulation of Laser Additive Manufacturing: Heat Transfer, Microstructure Evolutions and Mechanical Properties

Round 1

Reviewer 1 Report

REVIEWS MUST BE 100% complete, and I detected gaps in yours.

Papers structures is Ok, but the ISO standard must be followed fro the names.

I detected many names out of your revising, recent Works by Calleja, Gonzalez- Barrio, Lamikiz, and above all:

Inc718 LPBFed parts were developed in structure and in mechanical characteristic in a two parts keynotes, one is Stiffening near-net-shape functional parts of Inconel 718 LPBF considering material anisotropy and subsequent machining issues, Mechanical Systems and Signal Processing 168, 108675 and the root fundamentals is On the relationship between cutting forces and anisotropy features in the milling of LPBF Inconel 718 for near net shape parts in IJ of Machine Tools. There the structures with EBSD and the consequences in mechanical properties are deeply explained. The above works define a anisotropy performance and make step in simulations. Additive technologies goes on rapidly, and only some journals are able to propose the knowledge fresh, one was IJ machine Tool and Manufacture, with recent work explaining how is the structure and grain growth of LPBF methods, even the consequences on manufacturing  in On the relationship between cutting forces and anisotropy features in the milling of LPBF Inconel 718 for near net shape parts and in flexibility in other referred Works like https://doi.org/10.1016/j.ymssp.2021.108675 the Mechanical Systems and Signal processing journal itself. Both are Q1 journals, and the extension and Depth of the work helped us a lot for understanding additive and grain cohesions, please include and discuss. The say how grain grow and the effect of both VED and scanning strategy were discussed, and they are really important in additive. In your study, multilayer AM microstructures are simulated using the cellular automata-based (CA) solidification code ExaCA…OK, but you must check the new findings. So, a zig-zag subgranular  grain growth pattern has been identified with the 67° rotation strategy in lt30 and lt60 samples; However, the lower VED value in the lt60 sample cause high solidification rates that favored the increase of crystalline rotations and dislocations related to the lt30 sample, make the crystalline distribution not so concentrated.

Check also Mechanical Systems and Signal Processing very active recently in the field. A New Approach in the Design of Microstructured Ultralight Components to Achieve Maximum Functional Performance is the new idea in materials. I was studying the smaller particle to be printed

Author Response

Re: With the reminder from the reviewer, we noticed that the terms and nouns for AM used in the references are slightly different to the ISO standards. The different used nouns/terms can lead to confusions from readers. So, we gave an explanation in P.1 to illustrate the terms and nouns according to ISO / ASTM52900 – 15 for better readability. Please see the changes in P.1.

We searched the recommended author names with additive manufacturing in web-of-science. We selected the relevant works as references. Please see the added Ref.26 and Ref.141.

We downloaded the two recommended articles published Mechanical Systems and Signal Processing (Volume 168, 1 April 2022, 108675) and International Journal of Machine Tools and Manufacture (Volume 170, November 2021, 103801). They are really well written with high quality. We cited the two articles as Ref.27 and Ref.142. Please see the changes in P.2 and P.21.

Thanks for your work.

Reviewer 2 Report

The review is devoted to the modeling and simulation of heat transfer, the formation of microstructure and properties in additive manufacturing. The topic is relevant and in demand among researchers. The review is well-written and may be useful to readers of journals published by MDPI. However, while studying the presented paper, I had a few comments that can help improve the review.

1. In Fig. 2 is too significant a difference in font sizes. In Fig.2a and 2b they are very small, and in Fig. 2d is too big. I recommend bringing all fonts to the size used in Fig. 2a.

2. Fig. 3 in poor quality. It is necessary to increase the resolution and pointers (a), (b) ... (c) to reduce in size. Now they are very large. The words in the picture are cut off.

3. The text needs to be checked and typos edited. According to the text, "points" are not everywhere where necessary. After the formulas, if the sentence is complete, you need to put "." For example, line 156, 290, etc.

4. In Fig.8b, the scales need to be increased in size. Now they are impossible to read.

5. In the introduction, I propose to add in lines 34-42 the following publications on the topic that the authors did not include in the review:

https://doi.org/10.3390/ma12193269

https://doi.org/10.3390/ma13020461

https://doi.org/10.3390/machines8040079

https://doi.org/10.3390/ma11050742

6. The authors in the review, speaking about the simulation, do not name the programs that allow you to do this. From a practical point of view, it would be useful for readers to know the names of such programs and to find out their advantages and disadvantages, what calculation methods are incorporated in them.

Author Response

1. In Fig. 2 is too significant a difference in font sizes. In Fig.2a and 2b they are very small, and in Fig. 2d is too big. I recommend bringing all fonts to the size used in Fig. 2a.

Re: The font sizes are re-written to ensure the same font sizes in figures as suggested. Please see the revised Fig.2.

2. Fig. 3 in poor quality. It is necessary to increase the resolution and pointers (a), (b) ... (c) to reduce in size. Now they are very large. The words in the picture are cut off.

Re: We re-generated Fig.3 to increase the resolutions. Please see the revised Fig.3 in P.11.

3. The text needs to be checked and typos edited. According to the text, "points" are not everywhere where necessary. After the formulas, if the sentence is complete, you need to put "." For example, line 156, 290, etc.

Re: We checked the whole manuscript to avoid typo errors. Some of the errors like the equation numbers are coming from the editing of format to the submitted draft from the editorial office. We carefully checked it to avoid the typo errors. Moreover, we added “points” as suggested.

4. In Fig.8b, the scales need to be increased in size. Now they are impossible to read.

Re: We increased the fonts sizes in the contour bars in Fig.8b as suggested. Please see the revised Fig.8b in P.20.

5. In the introduction, I propose to add in lines 34-42 the following publications on the topic that the authors did not include in the review:

https://doi.org/10.3390/ma12193269

https://doi.org/10.3390/ma13020461

https://doi.org/10.3390/machines8040079

https://doi.org/10.3390/ma11050742

Re: The above articles are cited as references. Please see the newly added Refs. 7-10.

6. The authors in the review, speaking about the simulation, do not name the programs that allow you to do this. From a practical point of view, it would be useful for readers to know the names of such programs and to find out their advantages and disadvantages, what calculation methods are incorporated in them.

Re: Most of the programs are newly developed for the simulations of laser additive manufacturing with no specific names. Only the names of the methods can be definite. This is the reason that we listed the methods for the modelling and simulations of heat transfer, microstructures and mechanical properties. In thermal model, there are Gaussian and double ellipsoid heat source models with/without consideration of particle contributions. In microstructure model, there are MC, CA and PF models. In mechanical property model, there are precipitate evolution model, dislocation kinematic model and crystal plasticity model. This is also the motivation of current work. Thanks for your suggestion.

Thanks for your work.

Round 2

Reviewer 1 Report

Verison is Ok

Reviewer 2 Report

The authors of the article responded to my comments and submitted a revised version of the paper. I recommend it for publication in the presented version.