Effect of Precise TIG Welding Pool Temperature Control on Microstructure and Mechanical Properties of 7072 Aluminum Alloy Joints

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Clarify the novelty: the introduction mentions that most studies control temperature indirectly via welding parameters, but it does not sufficiently highlight how this study’s direct closed-loop temperature control differs from prior work. Please explicitly state the innovation and technological contribution of your temperature-control system in the Introduction or Abstract.

Improve methodological detail: in Section 2.1, describe the closed-loop temperature regulation system more clearly: How was the temperature measured and fed back?

Justify temperature selection: explain why 1750°C, 1825°C, and 1900°C were chosen as setpoints. Were these based on preliminary experiments or literature? Link these temperatures to the thermal behavior of 7072 alloy to strengthen the experimental design rationale.

Strengthen statistical analysis: mechanical property data (tensile strength, elongation, hardness) are presented as averages, but error bars or standard deviations are missing. Include statistical measures to support claims of uniformity and consistency, especially in Figures 8, 9, and 15.

Discuss microstructural mechanisms more deeply: in Sections 3.1 and 3.2, the discussion of grain morphology changes (equiaxed vs. columnar) is good, but link it more explicitly to thermal gradient (G) and solidification rate (R). Consider adding a quantitative analysis (e.g., grain size measurement) to support the “refined grain” claim.

Improve figure readability: Ensure all figures are clearly labeled, with scale bars in micrographs and distinct legends.

Clarify practical implications: the conclusion states that temperature control improves quality, but how does this translate to real-world applications? Briefly discuss the industrial relevance, potential limitations, and suggested implementation of the proposed control strategy in manufacturing or repair contexts.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors, the manuscript ‘Effect of Precise TIG Welding Pool Temperature Control on Microstructure and Mechanical Properties of 7072 Aluminum Alloy Joints’, Manuscript ID: jmmp-4116817, has some weaknesses that must be addressed.

Please find below some of the most significant issues:

1. The main advantage of the study is unknown from the Abstract It must be highlighted.
2. In the Introduction section, each of the references must be cited separately, when some justification for being cited are completed. Still, limitations of the previous results must be included. This is also crucial in defining the motivation of the main line of the study proposed.
3. Describing the material properties, e.g. ‘The weldability of 7xxx high-strength aluminum alloys is mainly limited by their high susceptibility to hot cracking and heat-affected zone softening.’, please add some justification of the type of material being studied. Why those alloys were considered except for a wide group of welded ones.
4. ‘After 60 seconds of welding to repair the cracks, cross-sectional samples of the weld joints were cut by wire cutting, then ground, polished, and etched.’ Why exactly 60 second of welding were proposed? It was not justified.
5. ‘Among the three welding current parameters, the residual height on the top side is greater than that on the bottom side under 170A and 175A welding currents.’ How can it be justified by its originates?
6. ‘From the weld zone to the heat-affected zone, the grain morphology in the fusion zone (FZ) transitions from planar crystals to cellular crystals and then to columnar dendrites.’ How can it straight refers to the results obtained?
7. ‘It is worth noting that precise temperature control directly affects the amount of heat input, increasing the molten pool's lifetime.’ It is not clear how the precision of the temperature control was obtained.
8. ‘The Al-Fe-Si phase usually has a complex crystal structure with strong atomic bonding, making it difficult for dislocations to move within it, resulting in high hardness but poor plasticity, thereby exhibiting brittleness.’ The complex nature of the phase is not discussed, what lacks the final advantage enhancements.
9. ‘The rapid solidification leads to defects such as porosity and incomplete fusion, severely compromising joint integrity.’ The level of solidification increasing is not discussed.
10. ‘Under identical heat input, phase transformation and grain growth proceed simultaneously…’ Why this simultaneous performance is received?
11. The Conclusions section do not emphasise the main purpose. It must be more visibly presented comparing to other information. The reader still cannot retrieve which result is of the greatest importance.

My final recommendation is a major revision of the manuscript, considering all of the above issues listed.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Paper can now be recommended for publication.