Effect of Process Parameters on Superelasticity of LPBF Ni-Rich Ni_51.3Ti_48.7 Shape Memory Alloy

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors

The article reflects the Ni-rich shape memory alloy by laser powder bed fusion process. Four sets of samples were prepared using various parameters using various laser power at various scanning velocity. Density has been investigated for various samples and plotted as the function of energy density. Compression test has been performed for various samples B1, B2, C1-C4, D2-D4 shows superelasticity behaviour in compression. As D1-D4 shows martensite temperature below - 100, so the rest of samples were considered. XRD analysis and other BSE shows other samples. The confusion starts here , then there is no flow and rule. XRD images are limited for samples , A4 shows shape memory behaviour, then XRD and optical microscopy shows out of phase. Ni content ( at. %) in powder and at different samples and mechanism of the samples were shown. However the intermetallic phases such as NiTi3 and oxide phases and NiTi2 were not support the superelasticity.

Conclusion should be specific.

finally laser melting process consumes a lot of powder and bed, NiTi powder is expensive and how author describe the cost effective process.

Comments on the Quality of English Language

There are some sentences not understandable or not complete, please check the manuscript carefully .

Author Response

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Reviewer 2 Report

Comments and Suggestions for Authors

The paper presents the influence of different process parameters of Ni-rich NiTi shape memory alloys obtained by LPBF. Superelasticity, phase ransformation behavior and microstructure evolution has been analyzed.

This study was well planned and validated. This can be considered for publication pending minor revision. Please find my comments below:

 

Line 104-105: After mechanical polishing, 8 s was etched in a mixed solution of HF ( is hydrogen fluoride not Hafnium?)

Line 123: The lowest energy density is for C1 or D1? Line 138 affirm that D1 sample presents macroscopic cracks. Please correct

Line 139: The reference is required for typical stages. I suggest : ASYMMETRY OF STRESS-STRAIN CURVES UNDER TENSION AND COMPRESSION FOR NiTi SHAPE MEMORY ALLOYS, YONG LIU, Z. XIE, J. VAN HUMBEECK and L. DELAEY, Acta mater. Vol. 46, No. 12, pp. 4325±4338, 1998

Fig. 7 (b) Replace A3 and A4 with B3 and B4

Line 246: Boiling point for Ni is 2913°C

 Line 272: Fig.13

 

Author Response

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Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors

The article is partly improved such as conclusion. However still there is an ambiguity to understand the flow. Authors didnot improve the results section based on queries.

If authors enlarge results section, it will be better understanding. The part is still missing the issues. Authors didnot address these issue seriously.

 

Regarding cost effective issue, ofcourse it saves after post processing work, however how author address the unused materials from the bed. As NiTi powder is super expensive, is it wise and environmental friendly to waste such materials.

Comments on the Quality of English Language

some sentences need to clarify, complex and hard to understand.

Line 132, disparate printing processes?

similarly

 

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

The article has done necessary correction. Only one suggestion, rather writing paragraph for XRD for selected samples, can authors upload supplementary files about the XRD of the rest of the samples. It could be useful.

 

After this additional implement, article could consider for publication.

Congrats

Author Response

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