Experimental Investigation of Al-CuMgMn Alloy Developed by Laser Beam Surface Modification for Wear Resistance

Round 1

Reviewer 1 Report

This manuscript proposes an lase modifying Al-CuMgMn alloy for improving their wear resistance. The topic is worth of investigation and the results are relevant for the field. The manuscript could be accepted subjected to a major revision. The main issues needing to be carefully addressed are summarized below.

1. It is interesting to see how deep from the surface the laser process affects. Cross-sectional analysis of the as-laser treated specimens can show the thickness of alloying depth, which is one of the important factors to control the wear kinetics of the alloyed layer.
2. The photograph is not clear in Figure 1 since we can’t see any important information.
3. The magnification of the two figures is inconsistent in Figure 4 so that we can’t get important details from microstructure of alloyed region image.
4. Laser parameters such as laser power, laser scanning rate, laser beam diameter should be given in list form.
5. Why the sample of laser alloying with 1700W laser power has maximum hardness? The author should talk about the underlying reasons scientifically and deeply.
6. How many points were tested to measure hardness of the laser alloyed surface layers? How about the repeatable of the experiments? What’s the hardness of the base material?
7. The conclusion “when the laser power is increased by 12%…”cannot be drawn from the manuscript. Please make it clear.
8. The Conclusions are weak, being mainly a repeat of the description of the results. Try numbering the Conclusions - it helps focus the mind. Write those matters that you want the reader to have learned from your work.

Author Response

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Many thanks for your time.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this work effect laser beam surface modification of Al-CuMgMn alloy was carry out. The paper is interesting, attractive topic for investigation, but some requires and corrections must be taken into account before publication in Metals.

Introduction: This part of paper need attention because is only weak point of paper. Introduction must provide a comprehensive critical review of recent developments in a specific area or theme that is within the scope of the journal, not only a list of published studies or a bibliometric one. I personally feel that this part of paper is not concise enough from a reader's perspective. The information authors can found in publications, e.g. 10.1007/s00170-018-2343-9, 10.3390/ma13153249, doi.org/10.1051/matecconf/201818802004, The other materials are also recommended to be included in the introduction, the paper will be more interested for reader, e.g. 10.1007/s00170-017-0775-2 , Methodology and discussion are curried out correctly in my opinion.

I think the paper can be accepted for publication after consideration of the Reviewer's suggestions

Author Response

Regarding the response to the review results, the file is attached. Find the attached file.

Many thanks for your time.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript investigated properties especially wear resistance of Al-CuMgMn alloy developed by laser beam surface modification. The research work has some Engineering values while little academic values. Additionally, the following issues need to be clarified.

1. The introduction need to be improved. The logical is not clear, it should focus on what this manuscript related, not just literature enumerate. Lots of literatures have no relationship to this manuscript.
2. It is stated that “The pre-placing of the powder was performed by making slurry of adhesive and powder”, how to avoid pores and other defects by using this method?
3. It is stated that “The particle size of each metal powder was 10μm” ，it should be the average value, how about the size distribution characteristics?
4. The laser spot diameter is 5.8mm, when you design the sample for tribology test, why the pin size is only 6mm? It is difficult to finish the laser movement.
5. In the laser alloyed samples, it is stated that density keeps changing with depth, why, the mechanism should be explained.

Author Response

Regarding the response to the review results, the file is attached. Find the attached file.

Many thanks for your time.

Author Response File: Author Response.pdf

Reviewer 4 Report

The authors conducted surface alloying of pure aluminum by using a CO₂ laser and proposeda modified Lancaster wear coefficient to assess the rate of wear for alloyed samples. Microstructure and surface morphology of alloyed samples was also studied in this paper. However, this manuscript is not innovative enough and not in a publishable state. It needs quite a bit of revision and there are some problems need to be solved as below:

1. In the abstract part, the author did not write the background of the research, the scientific problems to be solved and the necessity of research methods. These contents should be displayed in the abstract part.
2. The keyword part is a bit confusing. What does “laser surface” means? Maybe “surface modification” is a better alternative. And the authors should add material in the keyword section.
3. The author should summarize the literature review and point out the necessity of this research in the introduction. The author should also explain the innovation of research methods in this section.
4. There are some wrong symbols in the text, such as “10µ”, “120 mm x 30 mm x 10 mm”, “30 mm x 6 mm x 6 mm” and so on. The authors should modify them one by one until there are no errors in symbols.
5. The figures in the paper still have certain problems. Figure 1 is not clear at all and cannot show the necessary information. The key points of Figure 2, Figure 3, and Figure 8 are not prominent. The authors should mark the key points of the information in the figure.
6. The meaning of the third part of the article is not clear, it is more of other people’s theories, and the author’s method innovation is not shown.
7. Some conclusions in the article have no supporting basis. The authors made a conclusion that heat generated from laser power has an effect on the mechanical properties like hardness and wear resistances. But this conclusion is not supported by corresponding data.
8. Experimental results lack sufficient analysis and important research results are not highlighted. The authors only briefly described the experimental results without analyzing the reasons.

Author Response

Regarding the response to the review results, the file is attached. Find the attached file.

Many thanks for your time.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have carefully revised the content based my suggestions. I recommend this manuscript publish in Metals.

Reviewer 2 Report

The paper can be accepted for publication as it stands.

Reviewer 3 Report

The quality of Fig.2 can be improved

Reviewer 4 Report

The authors have addressed all concerns and the paper can be published as is.