Investigation of Deposition Parameters for Near-Beta Alloy Ti-55511 Fabricated by Directed Energy Deposition

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors in this work have focused on studying the influence of process parameters in the deposition using DOD technologies of the titanium alloy 55111. The work presented is excellent both from an organizational standpoint and in the method applied in analyzing the results. The authors have followed a statistical approach in organizing the experiments. Different geometries and their heat treatments have been carried out. Finally, the mechanical properties of the manufactured components were tested and then correlated with results found in literature. The reviewer compliments the work done and suggests publishing the work as it has been presented.

If I have to suggest something probably could be:

1) in the introduction take more emphasis of defect/constraints that could be derived by the DED process

2) in the conclusion report also what are the open challenge that must be solved to let this application in industrial environment

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Paper 'Investigation of Deposition Parameters for Near-Beta Alloy Ti-55511 Fabricated by Directed Energy Deposition' examines the effect of processing parameters and heat-treated conditions on the cube density, microstructure and mechanical properties of DED Ti-555111. This study is identifying promising deposition parameters fabrication of near-beta Ti-55511 alloy. Although the writing was good, some questions should be added to improve the quality of the manuscript.

1.     In section of Microstructural Evaluation, ‘Although there was some localized evidence of epitaxial growth between successive layers in condition 4 (Figure 10a), the bulk of the deposited material had an equiaxed grain structure. Condition 5 (Figure 10b) was entirely columnar and showed no evidence of a CET.’ The authors should explain clearly why the condition 4 shows epitaxial growth while condition 5 shows equiaxed grain structure.

2.     In section 3.4 of Mechanical Properties, the α and β phase have a significant on the tensile properties, can the authors calculate the ratio between phase α and phase β? Can give the reason for the proportion change and its effect on the tensile properties?

Author Response

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Reviewer 3 Report

Comments and Suggestions for Authors

1.Inconsistent capitalization of letters in full text images.

2.The impact of argon purity cannot be directly determined from lines 500 to 512.

3.There are few parts related to the conclusion and the content of the paper.

Author Response

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Reviewer 4 Report

Comments and Suggestions for Authors

The author investigated various parameters of Ti55511 alloy prepared by Direct Energy Deposition (DED) with the primary aim of identifying the optimal printing parameters. They employed the Design of Experiments (DOE) methodology from statistics to assess the influence of different parameters and ultimately determine the relatively optimized ones. However, there are still some issues with the article, and revisions are recommended before acceptance. I will now point out some problems and questions/suggestions:

Line164 Table2: What’s the reason for the selection of the single-track DED parameters? Any reference range or just a random pick?

 

Line189: Why MPIF standard? Normally the common tensile testing standard is the ASTM standard, what’s the advantage of the MPIF standard?

 

Line208: The contrast of Figure 2 is too high, and some black spots are visible, please use a high-resolution picture here.

 

Line216-229 Equation and table4: The author needs to use the same unit for Powder feed and Traverse Rate.

 

 

Line424: The alpha and beta phases should be indicated in Figure 10 since the author mentioned the contrast difference.

Author Response

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Author Response File: Author Response.docx