Characterizing the Tensile Behavior of Double Wire-Feed Electron Beam Additive Manufactured “Copper–Steel” Using Digital Image Correlation
, Kseniya Osipovich, Nikolay Shamarin, Andrey Chumaevskii *, Valery Rubtsov, Evgeny Moskvichev, Nickolai Savchenko * and Evgeny KolubaevRound 1
Reviewer 1 Report
The manuscript proposes a detailed investigation on the correlation between global and local mechanical behavior in multi-metallic samples obtained by double wire-feed electron beam additive technique.
The work is interesting, well articulated, and presents significant results. The main and most interesting part of the survey was carried out by exploiting the potential of the DIC. The SEM analysis, on the other hand, seems to stand alone, disconnected from the context.
As a general consideration, it is noted that the effect of diffusion phenomena at the interfaces between the two metals has not been taken into consideration. Do the authors believe that this is negligible, and can significant repercussions on the mechanical behavior at the interfaces be excluded?
Some other remarks are reported below:
1) Lines 19-20. It seems that words are missing. Check the sentence.
2) Lines 27-28. It seems that words are missing. Check the sentence.
3) Line 60. "foud" shouòd be "found".
4) Always specify acronyms the first time they appear. For example at line 105 make it clear that FSW stands for Friction Stir Welding.
5) Lines 129-133. The sentence is very confused, it must be reformulated clearly, also considering that it is the one that should declare the proposed work.
6) Lines 153-154. Why were the specimens etched? Specify the purpose.
7) Line 220. "Results" should be section 3, not section 2.
8) Lines 222-224. The same sentence is repeated twice.
9) Figure 4. Detail the 6 images included in the figure.
10) Line 264. After "...into several stages" enter a colon.
11) Line 343. It should be "unstable neck development", not "cervical".
12) Line 371. Crack stage should be the fourth stage, not the third one.
13) Subsection 3.3.6. At the beginning of the subsection explain why you apply the approach proposed in [23]. Make explicit the purpose of the use of this approach in the context of the proposed work.
14) Line 526. It should be "...modified Bezier algorithm".
15) Line 561. SEM and EDS analyses should not be reported as a subsection of section 3.3 dedicated to DIC, but in a separate section 3.4. Furthermore, as highlighted before, this part of the work seems disconnected from the previous investigation. Are there no correlations that should be highlighted? (some scant consideration in this sense is reported in the Discussion, nothing more)
16) Lines 579-583. The meaning of the sentence is confused. Rephrase it.
17) Lines 602-604. The sentence makes no sense. Check it.
18) Line 625. It should be "...mixture of both..."
Finally, as can be seen from many of the remarks above, the manuscript needs a careful revision of the language, as a lot of syntax slips can be found in it.
Author Response
As a general consideration, it is noted that the effect of diffusion phenomena at the interfaces between the two metals has not been taken into consideration. Do the authors believe that this is negligible, and can significant repercussions on the mechanical behavior at the interfaces be excluded?
A: Interfacial interaction occurs in both copper and iron parts. Cu particles with an average size £ of 5 μm are formed directly near the sharp boundary with the iron matrix. Fe particles with an average size of £ 10 µm are formed in a copper matrix. Since the interfacial interaction occurs at the boundary of Fe and Cu at an equal value of the concentration of the components, then in this area such structural elements as solid solutions of copper in iron, and iron in copper with additional mutual dissolution of alloying elements, mechanical mixtures of system components are formed. It should be noted that the dissolution and redistribution of alloying elements of steel occurs only inside the steel. This suggests that the formation of a mechanical mixture occurs rather quickly. The only factor in this redistribution is temperature. By definition, diffusion is well described by molecular kinetic theory. Therefore, it is important to take into account not only the contribution of temperature, but also time, since diffusion volumes are directly related to diffusion fluxes. Therefore, one should not consider the first Fick equation, but immediately turn to the second Fick equation, where C is the concentration of the substance, t is the time, x is the depth, and is the diffusion coefficient. Diffusion coefficient tabular quantitative value of the diffusion rate. In this work, the layer size will be described by the variable x, the deposition rate will correlate with the diffusion rate. Thus, the diffusion coefficient will be = 3.83 mm/s, and the time for the diffusion flow t = 0.26 s. Thus, the alloying elements that are part of the steel do not have time to diffuse, remain in the steel and do not form secondary phases with copper. But according to literary, possibly dissolution limited quantity copper (≈ 5.8 % at temperature 1083 °C) in γ-iron [30] and enough low solubility gland in copper (≈ 2.8 % at temperature 1083 °C) [31]. Therefore, in the future, only the effect of copper on iron and iron on copper will be considered without taking into account the contribution of Cr, Ni , and other alloying elements of steel. Thus, the phase composition in polymetallic samples made by the two-wire electro-beam additive technology is “austenitic steel γ-Fe (Cr, Ni)-copper epsilon-Cu ”. Moreover, the interphase boundaries of inclusions of steel and copper are sharp without the presence of transitional regions (Figure 4.).
- Lines 19-20. It seems that words are missing. Check the sentence.
A: Corrected
- Lines 27-28. It seems that words are missing. Check the sentence.
A: Corrected
- Line 60. "foud" should be "found".
A: Corrected
- Always specify acronyms the first time they appear. For example, at line 105 make it clear that FSW stands for Friction Stir Welding.
A: Corrected
- Lines 129-133. The sentence is very confused, it must be reformulated clearly, also considering that it is the one that should declare the proposed work.
A: Corrected
- Lines 153-154. Why were the specimens etched? Specify the purpose.
A: The metallographic tensile sample preparation (including chemical etching) allowed, first, a detailed study of the samples after fracture, and, second, etching made the samples contrast for DIC purposes. The related text has been added to the paper.
- Line 220. "Results" should be section 3, not section 2.
A: Corrected
- Lines 222-224. The same sentence is repeated twice.
A: Corrected
- Figure 4. Detail the 6 images included in the figure.
A: Corrected
- Line 264. After "...into several stages" enter a colon.
A: Corrected
- Line 343. It should be "unstable neck development", not "cervical".
A: Corrected
- Line 371. Crack stage should be the fourth stage, not the third one.
A: Crack stage is the third stage, because the strain diapason (Run-in stage) is related to specimen movement to adjust to the applied force. We called this stage “zero stage”. This is technical stage it is not closely connected with the mechanisms of the joint fracture.
- Subsection 3.3.6. At the beginning of the subsection explain why you apply the approach proposed in [23]. Make explicit the purpose of the use of this approach in the context of the proposed work.
A: It is well known that local shears play a cardinal role in the processes of deformation and fracture of solids. Such a character of the flow in the mechanics of a deformable solid is described by the shear component exy of deformation tensor. A vector field at simulation can be assigned with very small error which mostly defines by assumptions of a theory. However, experimental displacements are measured with some absolute error and the numerical differentiation increases this error. On the other hand, this approach does not allow to find the shear angle in the local area. The idea of new algorithm [23, in the revised version of the manuscript, this is reference number 28] is that the computer program numerically searches the shear angle in a local area where a shear functional is extremal. The value of the extremum functional is proportional to shear amplitude. Here, the pure shear in the area is the linear approximation of local field from the shear point. The related text has been added to the paper.
- Line 526. It should be "...modified Bezier algorithm".
A: Corrected
- Line 561. SEM and EDS analyses should not be reported as a subsection of section 3.3 dedicated to DIC, but in a separate section 3.4. Furthermore, as highlighted before, this part of the work seems disconnected from the previous investigation. Are there no correlations that should be highlighted? (some scant consideration in this sense is reported in the Discussion, nothing more)
A: Corrected section number for SEM and EDS and added text describing the relationships between SEM and EDS results and DIC results.
- Lines 579-583. The meaning of the sentence is confused. Rephrase it.
A: Corrected
- Lines 602-604. The sentence makes no sense. Check it.
A: Corrected
- Line 625. It should be "...mixture of both..."
A: Corrected
Author Response File: 
Author Response.pdf
Reviewer 2 Report
1. Pay attention to the writing style of the Abstract and Conclusion;
2. Scaleplate should be added to Figure 6, Figure 7, Figure 9 and Figure 10;
3. Isn't the annotation in Figure 8 (a) in English?
4. The formula format needs to be unified, Eqs. (3) and (4) should be right aligned ;
5. “Fig.19” is not bold;
6. The latest literature needs to be added, such as:
[1] Effect of uniform corrosion on mechanical behavior of E690 high-strength steel lattice corrugated panel in marine environment: a finite element analysis. Materials Research Express, 2021, 8 066510.
[2] Finite element analysis of pitting corrosion on mechanical behavior of E690 steel panel. Anti-Corrosion Methods and Materials, 2022, 28(12),7527-7536.
[3] Recent Advances in Corrosion Research of Biomedical NiTi Shape Memory Alloy. Rare Metal Materials and Engineering, 2021, 50(11): 4165-4173.
Author Response
- Pay attention to the writing style of the Abstract and Conclusion;
A: Corrected
- Scaleplate should be added to Figure 6, Figure 7, Figure 9 and Figure 10;
A: Corrected
- Isn't the annotation in Figure 8 (a) in English
A: Corrected
- The formula format needs to be unified, Eqs. (3) and (4) should be right aligned;
A: Corrected
- “Fig.19” is not bold;
A: Corrected
- The latest literature needs to be added, such as:
[1] Ming Liu Effect of uniform corrosion on mechanical behavior of E690 high-strength steel lattice corrugated panel in marine environment: a finite element analysis. Materials Research Express, 2021, 8 066510. https://doi.org/10.1088/2053-1591/ac0655
[2] Ming Liu Finite element analysis of pitting corrosion on mechanical behavior of E690 steel panel. Anti-Corrosion Methods and Materials, 2022, 28(12),7527-7536. https://doi.org/10.1108/ACMM-11-2021-2571
[3] Recent Advances in Corrosion Research of Biomedical NiTi Shape Memory Alloy. Rare Metal Materials and Engineering, 2021, 50(11): 4165-4173.
A: We have added sources [1] and [2] to References, but article [3] does not suit us in terms of subject matter
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The paper can be published in current form
Author Response
