Review Reports - Shielding Gas Effect on Dendrite-Reinforced Composite Bronze Coatings via WAAM Cladding: Minimizing Defects and Intergranular Bronze Penetration into 09G2S Steel

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1) Introduction:

The second paragraph (lines 60-74) contains no information important for the conducted research and is therefore needless. It can be omitted.

As described in chapter 2.2 WAAM Cladding Parameters, the chosen deposition technique was weld cladding by MIG and MAG process. It is generally known that for welding of non-ferrous alloys, suitable shielding gases do not contain carbon dioxide, because at temperatures of a welding arc CO2 molecules disintegrate, and free oxygen atoms oxidize the weld pool, leading to weak joints, poor surface smoothness, and potential cracking. And as air contains about 20 % oxygen, it also causes excessive oxidation and porosity. Hence, the results obtained should be expected in advance. So why were the experiments with CO2, Ar+18% CO2 and air made?

Therefore, it is crucial to discuss motives for selecting these gases, and arguments that justify the choice of these active gases must be specified in the text. Was it perhaps to see whether the results would still be acceptable despite cheaper gases? If so, this should be stated.

As stated in lines 104-106, “there are no detailed studies on the influence of various shielding gases on the microstructural evolution, phase stability, or diffusion behavior specifically at the substrate-coating interface”. Newertheles, in the literature reporting bronze coating by WAAM process probably also the utilized shielding gases were listed. Please add this information.

4) Figure 1:

Figure 1 is misleading. On the left side (WAAM Process Scheme) a drawing of a torch is shown and in the drawing an inscription and an arrow point out a “consumable electrode”. That's fine. What is disturbing, however, is the wire that is coming from the left side from the wire feeder (not through the torch). This suggests that two wires were used at the same time: one was fed through the torch, and the other through an additional feeder bypassing the torch. If this was indeed the case, it should be clearly stated in the text. However, if only the wire fed through the torch was used (which is normal for MIG/MAG welding and what I conclude from the description of the equipment in the text), the image should be corrected.

5) Table 2:

The flow rates of shielding gases are missing in Table 2. Please add a column with flow rates.
For the sample Bronze 1, as atmosphere “no gas” is specified. But neither in the text nor in Table 2 is it explained, what exactly does no gas/or welding in air mean. Does it mean that no gas was blowing through the torch (flow rate = zero)? Or what would be even worse, that air was blowing through the gas nozzle with a certain flow rate? Please add the explanation.

6) Welding speed

What was the welding speed? Please state it. I suggest adding a column containing welding speeds into Table 2.

Welding current of 150 A and welding voltage of 16 V result in short-circuit metal transfer. As explained in lines 156-158, thereby a low heat input was achieved. Nevertheless, short-circuit transfer allows only moderate deposition rates. Hence the question, why pulsed arc transfer which allows higher welding speeds and higher deposition rates combined with even less spatter was not also considered for welding with pure Ar and Ar-rich mixture? Please add an explanation.

As stated in the text, for all experiments the same set of welding parameters was applied. Nevertheless, different gases have different heat conductivities, result in different surface tensions etc., and therefore have influence on local peak temperatures, temperature fields in the melt pool and in the work piece, viscosity of the melt etc. Therefore, one set of parameters can represent the optimum for one shielding gas, while for another gas the same set is not necessarily optimal.

Please add a discussion on this topic.

Strictly use SI conform units: nanometer instead of angstrom.

10) Lines 239-241:

“The lack of shielding gas during WAAM introduces a highly reactive environment, promoting the rapid diffusion of copper from the bronze coating along the austenite grain boundaries.”

The results presented do indeed lead to this conclusion. But is there an explanation for why copper diffusion into the substrate is faster when there is no protective gas? If there is, include the explanation in the text. Otherwise make a statement that this is your conclusion based on the comparison with results obtained with shielding gases.

11) Lines 458-460 and 470-473:

“In summary, this comparative study of WAAM-deposited Bronze 1, Bronze 2, Bronze 3, and Bronze 4 coatings highlights the dominant role of both process parameters and shielding atmosphere on the resulting microstructure and interfacial characteristics. “

“Ultimately, this investigation underscores the critical importance of carefully optimizing WAAM process parameters and utilizing appropriate shielding techniques to tailor coating properties for specific applications, with Bronze 2 serving as a benchmark for achieving a high-quality, well-controlled microstructure and interface.”

12)

As all experiments were performed with equal welding parameters, the presented study only illustrates the importance of shielding gas, while no conclusions on the impact of other process parameters can be drawn.

Author Response

Response to Reviewer 2

First of all, we would like to say that we are very grateful for your very valuable comments.

1) Introduction:

The second paragraph (lines 60-74) contains no information important for the conducted research and is therefore needless. It can be omitted.

Response: We appreciate your suggestion. However, we believe that retaining the second paragraph (lines 60–74) is essential for maintaining the completeness and scope of the introduction. While these materials may not be the direct focus of our research, their mention allows us to establish a clear baseline of existing technologies and to better frame the unique contributions and potential benefits of bronze coatings in comparison. Therefore, we respectfully request to retain it.

2) As described in chapter 2.2 WAAM Cladding Parameters, the chosen deposition technique was weld cladding by MIG and MAG process. It is generally known that for welding of non-ferrous alloys, suitable shielding gases do not contain carbon dioxide, because at temperatures of a welding arc CO2 molecules disintegrate, and free oxygen atoms oxidize the weld pool, leading to weak joints, poor surface smoothness, and potential cracking. And as air contains about 20 % oxygen, it also causes excessive oxidation and porosity. Hence, the results obtained should be expected in advance. So why were the experiments with CO2, Ar+18% CO2 and air made?

Response: We thank the reviewer for raising this critical point regarding the shielding gas selection. We fully acknowledge the known detrimental effects of CO₂ and oxygen-containing gases on the weld quality of non-ferrous alloys like bronze during arc processes. Our selection of pure Ar, CO₂, 82% Ar + 12% CO₂ mixture and air was deliberate and forms a core part of this investigation. The primary motive was specifically to systematically investigate the tolerance limits of the WAAM process for bronze cladding when utilizing less ideal, lower-cost, and more accessible shielding gases. We have added this clarification to the text.

“As a core aspect of this study, and to provide a more comprehensive evaluation of the WAAM process, an N₂/O₂ atmosphere (no shielding gas) and various shielding gas compositions, Ar, CO₂, and an Ar/CO₂ mixture, were intentionally employed. This decision was motivated by the desire to systematically assess the sensitivity of the WAAM process for bronze cladding, under constant parameters, to the presence of atmospheric contaminants. Such an approach allowed for specific quantification of the impact of these different shielding atmospheres, chosen for their varying cost and availability, on weld characteristics. Furthermore, due to the use of a fixed parameter set, the effects of these gases could be examined without the complexities introduced by parameter adjustments, enabling a direct comparison. Through this rigorous comparison, the aim is to determine the operating limits of the WAAM process and identify potential mitigation strategies when more economical or readily accessible shielding gases are necessary.”

3) As stated in lines 104-106, “there are no detailed studies on the influence of various shielding gases on the microstructural evolution, phase stability, or diffusion behavior specifically at the substrate-coating interface”. Nevertheless, in the literature reporting bronze coating by WAAM process probably also the utilized shielding gases were listed. Please add this information.

Response: Thank you for raising this point. While we acknowledge that the literature concerning arc cladding of bronze, including our cited references [38], [39], and [40], implicitly involves the use of a shielding gas to facilitate the arc process, these studies do not provide any specific information regarding the type of shielding gas employed, let alone any investigation into its influence on the process. This absence of detailed information regarding the shielding environment further reinforces our core argument: there is a significant knowledge gap in understanding how different shielding gases affect the microstructural evolution, phase stability, and diffusion behavior specifically at the substrate-coating interface in WAAM bronze cladding. Our study directly addresses this gap, providing novel insights that are currently lacking in the existing literature.

4) Figure 1:

Response: Thank you for your careful reading of the manuscript and the valuable comment regarding Figure 1. We have corrected the Figure 1 to accurately depict the GMAW-WAAM process used in our study, clearly showing that the wire is fed through the torch, as is standard for this technique.

Figure 1. Schematic illustration of the GMAW-WAAM cladding process and a general cross-sectional view of the specimens.

5) Table 2:

The flow rates of shielding gases are missing in Table 2. Please add a column with flow rates.
For the sample Bronze 1, as atmosphere “no gas” is specified. But neither in the text nor in Table 2 is it explained, what exactly does no gas/or welding in air mean. Does it mean that no gas was blowing through the torch (flow rate = zero)? Or what would be even worse, that air was blowing through the gas nozzle with a certain flow rate? Please add the explanation.

Response: Thank you for your valuable feedback.

We have added a column to Table 2 specifying the shielding gas flow rates.
You are correct; ‘no gas’ for Bronze 1 indicates that no gas was actively supplied through the torch, resulting in a flow rate of zero. We have clarified this in the Table 2.

Table 2. Parameters of WAAM cladding process.

Sample	Сurrent, A	Voltage, V	Wire feed rate, m/min	Welding speed, mm/min	Flow rate, L/min	Shielding gas
Bronze 1	150	16	3.6	250	-	-
Bronze 2					10	Ar
Bronze 3						82% Ar + 12% CO₂
Bronze 4						CO₂

6) Welding speed

What was the welding speed? Please state it. I suggest adding a column containing welding speeds into Table 2.

Response: Thank you for your valuable feedback. Welding speed is a really important WAAM parameter and we’ve added it to Table 2.

7) Welding current of 150 A and welding voltage of 16 V result in short-circuit metal transfer. As explained in lines 156-158, thereby a low heat input was achieved. Nevertheless, short-circuit transfer allows only moderate deposition rates. Hence the question, why pulsed arc transfer which allows higher welding speeds and higher deposition rates combined with even less spatter was not also considered for welding with pure Ar and Ar-rich mixture? Please add an explanation.

Response: We thank you for this insightful question regarding pulsed arc transfer. Our primary objective in this study was to specifically evaluate the effectiveness of different shielding gases under a consistent WAAM parameter set, including the short-circuit transfer mode, to isolate the effects of gas composition. While we acknowledge the benefits of pulsed arc transfer for higher deposition rates and lower spatter, exploring that mode with pure Ar and Ar-rich mixtures was beyond the scope of this particular investigation. However, we agree that this would be a valuable avenue for future research to optimize both deposition rates and weld quality.

8) As stated in the text, for all experiments the same set of welding parameters was applied. Nevertheless, different gases have different heat conductivities, result in different surface tensions etc., and therefore have influence on local peak temperatures, temperature fields in the melt pool and in the work piece, viscosity of the melt etc. Therefore, one set of parameters can represent the optimum for one shielding gas, while for another gas the same set is not necessarily optimal.

Please add a discussion on this topic.

Response: We appreciate your comment regarding the potential for different optimal parameter sets for each shielding gas. Our intention was not to find the absolute best parameters for each gas, but rather to conduct a comparative analysis of their performance under a fixed set of conditions. This allows us to directly assess their relative suitability for WAAM bronze cladding, given a pre-defined operating window. We recognize that further optimization with individually tailored parameters could yield improved results for each gas, and this is an interesting area for future study.

9) Strictly use SI conform units: nanometer instead of angstrom.

Response: We sincerely appreciate your diligence in checking the units. We agree that adhering strictly to SI-conform units enhances clarity and consistency across the manuscript. We have converted all instances of Angstroms (Å) to nanometers (nm) throughout the text, particularly for lattice parameters, to ensure compliance with SI standards.

10) Lines 239-241:

“The lack of shielding gas during WAAM introduces a highly reactive environment, promoting the rapid diffusion of copper from the bronze coating along the austenite grain boundaries.”

Response: Thank you for this insightful comment. We agree that further explanation regarding the enhanced copper diffusion in the absence of shielding gas is necessary. The observed phenomenon is indeed our conclusion based on a comparative analysis of the results obtained with and without shielding gases. We will add the following explanation to the text to clarify the mechanism:

“The lack of shielding gas during WAAM introduces a highly reactive environment, promoting the rapid diffusion of copper from the bronze coating along the austenite grain boundaries. This conclusion is based on a comparative analysis with experiments using inert shielding gases. In the absence of protection, the molten pool is directly exposed to atmospheric oxygen and nitrogen, resulting in: (1) increased oxidation of copper, creating a driving force for diffusion into the iron-rich substrate; (2) disruption of any normally passivating oxide layer, further promoting direct contact and diffusion; and (3) potentially higher and more unstable local temperatures due to arc instability without the controlled cooling effect of shielding gas, enhancing atomic mobility.”

11) Lines 458-460 and 470-473:

Response: Thank you for pointing out the potential misinterpretation in lines 458–460 and 470–473. We appreciate your diligence in ensuring that our conclusions align with the experimental parameters. You are correct that, as our experiments were conducted with a fixed set of WAAM parameters, we cannot definitively draw conclusions about the influence of those parameters themselves. Our focus was solely on evaluating the impact of different shielding atmospheres under identical process conditions.

Therefore, we have revised those sentences to remove any implication that we assessed the effects of varying WAAM parameters. The revised statements emphasized the dominant role of the shielding atmosphere on the resulting microstructure and interfacial characteristics, and the appropriateness of Bronze 2 as a benchmark:

“In summary, this comparative study of WAAM-deposited Bronze 1, Bronze 2, Bronze 3, and Bronze 4 coatings highlights the dominant role of shielding atmosphere on the resulting microstructure and interfacial characteristics.”

“Ultimately, this investigation underscores the critical importance of utilizing appropriate shielding techniques to tailor coating properties for specific applications, with Bronze 2 serving as a benchmark for achieving a high-quality, well-controlled microstructure and interface.”

12) As all experiments were performed with equal welding parameters, the presented study only illustrates the importance of shielding gas, while no conclusions on the impact of other process parameters can be drawn.

Response: Thank you for your insightful comment. We appreciate your pointing out that our study primarily illustrates the importance of the shielding gas due to the constant WAAM parameters. You are correct that the primary objective of this research, as reflected in the title, abstract, and introduction, was to specifically investigate the influence of different shielding gases on bronze coating penetration into the substrate under consistent WAAM conditions. We understand your concern regarding the importance of other process parameters, and we acknowledge that exploring their influence is a crucial area for future research, which we plan to pursue in subsequent investigations.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presents an experimental investigation into the influence of shielding gas composition on the microstructure, wear, and corrosion behavior of wire arc additive-manufactured (WAAM) bronze coatings on low-carbon steel substrates. The experimental methodology is generally sound and the findings are interesting; however, the manuscript would benefit from structural and editorial improvements, deeper scientific discussion, and better data presentation to strengthen its impact.

The Abstract is well-drafted but somewhat descriptive. It should emphasize the quantitative improvements (e.g., reduction in corrosion rate, increase in hardness) attributed to each gas condition to highlight novelty.
The Introduction is informative but lengthy. Condensing background material and more clearly defining the research gap—specifically, the lack of systematic comparison of shielding gases for WAAM bronze coatings—would improve readability.
The materials and process parameters (current, voltage, travel speed, gas flow rate, deposition speed, interlayer temperature, etc.) should be provided in a clear table format for reproducibility.
The gas compositions (pure Ar, Ar–CO₂ mixtures, etc.) should be quantitatively specified (e.g., 98% Ar + 2% CO₂).
More details on substrate surface preparation and preheating (if any) are needed to ensure consistency across samples.
For corrosion testing, specify the electrolyte composition, potential range, scan rate, and reference/counter electrodes used.
The section organization can be improved by separating microstructural characterization, mechanical properties, and corrosion/wear analysis into distinct subsections.
Discussion should link observed trends (e.g., porosity reduction, intermetallic formation) to underlying metallurgical mechanisms, such as oxygen pickup or arc stability changes due to gas composition.
The manuscript discusses results primarily from an empirical perspective. Including insights into thermodynamic or kinetic mechanisms (e.g., oxidation reactions, gas-metal interactions) would strengthen the analysis.
The synergy between wear and corrosion performance could be addressed—does the improved corrosion resistance correlate with reduced oxide formation or improved interfacial bonding?
The English writing is clear but would benefit from grammatical polishing and sentence simplification (several long sentences could be split for clarity).

Author Response

Response to Reviewer 3

First of all, we’re extremely grateful for your very helpful and insightful comments. Your feedback is much appreciated. While we acknowledge the importance of wear and corrosion resistance, we have the impression there may have been a partial overlap with another manuscript during the review process. The reviewer’s comments mention wear and corrosion resistance, aspects that were not investigated within the scope of this submitted manuscript. As clearly outlined in Section 4. Conclusions and Future Prospects, these topics represent intended directions for our future research, and are not currently part of the present research.

1. The Abstract is well-drafted but somewhat descriptive. It should emphasize the quantitative improvements (e.g., reduction in corrosion rate, increase in hardness) attributed to each gas condition to highlight novelty.

Response: We appreciate the reviewer’s suggestion to enhance the abstract with quantitative improvements. We have strived to include the most relevant numerical data pertaining to this study’s objectives. This research focuses on coating defectiveness, wettability, and intergranular penetration (IGP). We have detailed in the abstract the quantitative Rietveld refinement results for the α-Fe volume fraction (~5%), lattice parameters for α-Cu and α-Fe, and microstrain, all of which directly pertain to these focus areas. While the Ar-atmosphere coating displayed a lower microhardness (130 HV_0.1), we emphasize in the abstract that this value was remarkably consistent across the entire analyzed area, signifying significant structural homogeneity which is a key parameter for mechanical behavior of coatings.

Furthermore, as we previously clarified, wear resistance and corrosion rates were deliberately outside the scope of the current study. Therefore, we did not obtain any numerical data related to these properties. As outlined in Section 4. Conclusions and Future Prospects, we are planning to investigate these aspects in our future research, and will certainly incorporate quantitative results in subsequent publications.

2. The Introduction is informative but lengthy. Condensing background material and more clearly defining the research gap—specifically, the lack of systematic comparison of shielding gases for WAAM bronze coatings—would improve readability.

Response: We sincerely thank the reviewer for the assessment that the Introduction is “informative”. We recognize the suggestion to condense the background material and sharpen the definition of the research gap.

We respectfully wish to emphasize that the Introduction, as structured, serves a crucial dual purpose in our manuscript: first, to establish the indispensable industrial relevance of bronze coatings, and second, to sequentially build the rationale that leads directly to the stated research gap. The depth of the background is intentionally provided to fully justify the novelty of systematically comparing these four distinct atmospheric conditions for WAAM bronze cladding.

Furthermore, we observe that balancing the length of the Introduction often presents a challenge in scientific review, as some reviewers favor extensive context while others prefer brevity. Since the reviewer confirmed the section is “informative”, we would strongly argue that the current detail supports the novelty claim for this systematic atmospheric study.

Therefore, to maintain the logical flow and comprehensive justification for our comparative experimental design, we kindly request that the reviewer permit us to retain the current structure of the Introduction.

3. The materials and process parameters (current, voltage, travel speed, gas flow rate, deposition speed, interlayer temperature, etc.) should be provided in a clear table format for reproducibility.

Response: Thank you for your insightful comment regarding reproducibility. We agree that providing clear information about materials and process parameters is essential.

The materials used in this study are already described in detail in Table 1, including relevant compositional information. To directly address your concern about the WAAM process parameters, we have now significantly expanded Table 2 to include key parameters critical for reproducibility, namely:

Welding speed, mm/min
Flow rate, L/min

Table 2. Parameters of WAAM cladding process.

Sample	Сurrent, A	Voltage, V	Wire feed rate, m/min	Welding speed, mm/min	Flow rate, L/min	Shielding gas
Bronze 1	150	16	3.6	250	-	-
Bronze 2					10	Ar
Bronze 3						82% Ar + 12% CO₂
Bronze 4						CO₂

We believe these additions to Table 2, in conjunction with the existing details about current, voltage, shielding gases and other WAAM deposition parameters, now provide a comprehensive overview of the experimental setup, facilitating the reproducibility of our study.

4. The gas compositions (pure Ar, Ar–CO₂ mixtures, etc.) should be quantitatively specified (e.g., 98% Ar + 2% CO₂).

Response: Thank you for pointing out the need for precise gas composition specifications. We appreciate the chance to clarify this point. In the Abstract, Introduction, and Experimental section, we have consistently specified the composition of our single mixture used as 82% Ar + 18% CO₂, and have introduced the abbreviation Ar/CO₂ for that specific mixture to maintain clarity and conciseness throughout the manuscript. We trust that this consistent use of both the full composition and abbreviation removes any ambiguity.

5. More details on substrate surface preparation and preheating (if any) are needed to ensure consistency across samples.

Response: We thank the reviewer for highlighting the importance of specifying substrate preparation details. To address this comment and ensure clarity for reproducibility, we have expanded the Experimental Section to provide the following information regarding substrate preparation in Subsection 2.1. Materials:

“Prior to WAAM processing, the substrate surface was thoroughly cleaned to remove any existing oxides, scale, or contaminants using abrasive blasting with alumina particles, followed by degreasing with acetone. This cleaning process ensures a consistent surface condition for wetting. The average surface roughness (Ra) of ~1 μm was measured using a model 250 profilometer (JSC “Caliber”, Moscow, Russia).”

It’s important to note that, in our experiments, no preheating of the substrate was employed. We believe these additions now provide a comprehensive description of the substrate preparation process.

6. For corrosion testing, specify the electrolyte composition, potential range, scan rate, and reference/counter electrodes used.

Response: Thank you for your comment about the need to specify details of corrosion testing. We recognize the importance of these details for studies that include corrosion analysis. However, as we clarified in our earlier response, corrosion testing was not performed as part of this study and is outside the current scope, as discussed in Section 4. Conclusions and Future Prospects. Therefore, specifications for electrolytes, potential ranges, scan rates, and electrode setup are not applicable to this manuscript.

7. The section organization can be improved by separating microstructural characterization, mechanical properties, and corrosion/wear analysis into distinct subsections.

Response: We appreciate the reviewer’s suggestion regarding further subdivision of the manuscript structure. We have carefully organized the manuscript with the goal of optimizing readability and logical flow.

As demonstrated in the Table of Contents (or flow of sections), the manuscript is already structured into distinct main sections that cover the necessary analyses: Microstructural Characterization (including OM, SEM, EDS, XRD) is covered thoroughly, and Mechanical Properties (specifically microhardness testing) are addressed separately.

Therefore, the authors feel that the current sectional organization is sufficiently detailed and robust—perhaps even providing a comprehensive structure in the context of the included experimental data—and will allow for optimal reader comprehension.

8. Discussion should link observed trends (e.g., porosity reduction, intermetallic formation) to underlying metallurgical mechanisms, such as oxygen pickup or arc stability changes due to gas composition.

Response: Thank you for highlighting the importance of linking observed trends with underlying metallurgical mechanisms. We have carefully considered your suggestion and have revised the Discussion section to incorporate further analysis of the potential mechanisms driving the observed phenomena.

Specifically, we have added the following text:

We believe this addition now directly addresses the role of oxygen pickup and arc stability (related to gas composition) in the observed diffusion and intergranular penetration.

9. The manuscript discusses results primarily from an empirical perspective. Including insights into thermodynamic or kinetic mechanisms (e.g., oxidation reactions, gas-metal interactions) would strengthen the analysis.

Response: We appreciate the reviewer’s insightful comment regarding the need to integrate more thermodynamic or kinetic mechanisms into the Discussion.

We agree that a significant portion of our results stems from empirical observation, which is inherent to systematic comparative studies of processing parameters. However, we respectfully wish to point out that throughout the text, the authors consistently provide concrete mechanistic hypotheses concerning the deterioration of microstructure (in particular, see the response to previous comment 8). Specifically, we link the observed trends to:

Degradation of Interfacial Integrity (Wettability).
Increased Defect Formation (Porosity and Cracks).

Most critically, the Enhanced Intergranular Penetration (IGP) of the bronze coating into the steel substrate, manifesting as the formation of characteristic “bronze whiskers.”

Investigating and mechanistically explaining this IGP phenomenon was the primary goal of the present research, and our analysis directly correlates the varied gas environments to the extent of this penetration. While we do not delve into detailed computational thermodynamics for oxidation or arc stability (as these were outside the established scope), our conclusions are firmly rooted in comparative analyses of diffusion driven by the presence/absence of reactive atmospheres.

We believe this focus on the observed, structure-governing mechanisms provides a strong foundation for the current analysis, justifying the empirical approach taken.

10. The synergy between wear and corrosion performance could be addressed—does the improved corrosion resistance correlate with reduced oxide formation or improved interfacial bonding?

Response: We thank the reviewer for the insightful question about the potential synergy between wear and corrosion performance. The specific question about the impact of oxide formation and interfacial bonding is highly relevant to understanding long-term performance. However, as repeatedly clarified, the scope of the current study is limited to examining the influence of different shielding gas conditions on the initial clad layer microstructure and wettability during deposition. In this manuscript, we did not conduct any wear or corrosion testing, precluding us from directly correlating those properties with our microstructural findings.

Your question regarding synergy is highly valuable. In Section 4. Conclusions and Future Prospects, we specifically outline that investigating the wear and corrosion behavior of these WAAM-processed bronze coatings, and understanding potential synergistic relationships between these properties, are key areas for future research efforts building on this initial study.

11. The English writing is clear but would benefit from grammatical polishing and sentence simplification (several long sentences could be split for clarity).

Response: Thank you for pointing out areas for improvement in the English writing. Prior to submission, we made efforts to ensure the clarity and accuracy of the writing. However, we recognize the value of an external perspective and will thoroughly review the manuscript again, paying specific attention to simplifying long sentences and correcting grammatical nuances to enhance readability.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All comments were appropriately addressed, and where necessary, adequate improvements were made in the text. Therefore, my recommendation to the editor was “accept in present form”.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have adequately addressed all the comments and provided clear revisions and explanations where necessary. The responses are thorough, and the revised manuscript reflects the suggested improvements. I recommend proceeding with the next steps in the publication process.