Electrical Explosion Synthesis, Oxidation and Sintering Behavior of Ti-Al Intermetallide Powders
, Elena Glazkova 1,*, Nikolay Rodkevich 1 and Nikita Toropkov 1,2Round 1
Reviewer 1 Report
The manuscript is devoted to study the Electrical Explosion Synthesis, Oxidation and Sintering Behavior of Ti-Al Intermetallide Powders. Authors presented interesting experimental results, however, there are some comments need to be addressed before publish in Metals.
1- In introduction section authors has claimed that “The disadvantage of this method is a higher evaporation rate of aluminum compared to titanium which can lead to low titanium content in the nanoparticles”. But when Al evaporates Ti rich particle should remain due to low Al content. Can you confirm your statement.
2- In Materials and Methods: It is required to show the references of equation (1), (2) and E/Es as well.
3- In Fig. 4, (a) and (c) are same images! Additionally particles in (b) looks larger than (a).
4- In caption of Fig. 5, you should sperate the conditions with parenthesis. In the current way it looks like an equation.
5- In 3.3. Ti-Al particle formation; it would be better to explain the phase formation based on/showing phase diagram. Additionally, following statement should be revised seems not clear. “In the case of sample 1 … depleted in aluminum”.
6- In equation (4) temperature T was not defined.
7- On page 10/12, after discussion on the oxygen content of produced particles it is required to add the following statement with related references to show the positive effect of oxygen in strengthening of Ti alloys. “However, it is difficult to eliminate the oxygen during fabrication of Ti powders. Additionally, the existance of small amount of oxygen results in strengthening of Ti alloys”.
[Ref] Strengthening evaluation and high-temperature behavior of Ti–Fe–O–Cu–Si alloy
[Ref] Microstructure globularization of high oxygen concentration dual-phase extruded Ti alloys via powder metallurgy route
8- In XRD evaluation of sintered powders at 1000 C Fig. 9, why you did not identify γ-TiAl phase while peaks are visible? In addition, Ti3.3Al or Ti3Al?
Author Response
Dear Reviewer!
Thank you for your valuable comments on our manuscript. In the revised version of the manuscript, all your comments and suggestions were considered and carefully addressed.
The manuscript is devoted to study the Electrical Explosion Synthesis, Oxidation and Sintering Behavior of Ti-Al Intermetallide Powders. Authors presented interesting experimental results, however, there are some comments need to be addressed before publish in Metals.
1- In introduction section authors has claimed that “The disadvantage of this method is a higher evaporation rate of aluminum compared to titanium which can lead to low titanium content in the nanoparticles”. But when Al evaporates Ti rich particle should remain due to low Al content. Can you confirm your statement.
Sentence “The disadvantage of this method is a higher evaporation rate of aluminum compared to titanium which can lead to low titanium content in the nanoparticles.” has been expanded to clarify the assumption of the report cited:
Lines 73-76. The disadvantage of this method is a higher generation rate of aluminum vapor compared to that of titanium vapor results in the lower Ti content. Al and Ti atoms in vapor state collide and grow into Al–Ti clusters. The lower Ti content in vapor can lead to low Ti content in the nanoparticles.
2- In Materials and Methods: It is required to show the references of equation (1), (2) and E/Es as well.
Equation (1) and E/Es were used when describing the electrical explosion of wires to estimate the energy introduced into the wire, and the amount of overheating of the metal in the wire. Equation (2) was used to calculate the average particle size.
Line 118. We have added the references [21,22] for equation (1).
Line 119. We have added the references [19,21] for E/Es
Line 127. We have added the reference [19] for equation (2).
Due to changes in the text, the numbering of references in the References section has changed:
- M.I. Lerner, A.V. Pervikov, E.A. Glazkova, N.V. Svarovskaya, A.S. Lozhkomoev, S.G. Psakhie, Structures of binary metallic nanoparticles produced by electrical explosion of two wires from immiscible elements, Powder Technol. 288 (2016) 371–378. DOI: 10.1016/j.powtec.2015.11.037
- G.S. Sarkisov, P.V. Sasorov, K.W. Struve, D.H. McDaniel, State of the metal core in nanosecond exploding wires and related phenomena J. Appl. Phys. 96 (2004) 1674-1686. https://doi.org/10.1063/1.1767976.
- A. Pervikov, E. Glazkova, M. Lerner, 2018. Energy characteristics of the electrical explosion of two intertwined wires made of dissimilar metals. Physics of Plasmas. 25, 070701. https://doi.org/10.1063/1.5034184.
- U. R. Kattner, J.C. Lin, Y. A. Chang, Thermodynamic Assessment and Calculation of the Ti-Al system, Metall. Trans. A. 23 (1992) 2081–2090. https://doi.org/10.1007/BF02646001.
3- In Fig. 4, (a) and (c) are same images! Additionally particles in (b) looks larger than (a).
Unfortunately, an error has occurred.
Line 181. We have replaced Figure 4 (c). Particles in (b) looks larger than (a) because images of nanoparticles do not directly reflect their size. Particle size is an integral value calculated by equation (2) based on the specific surface area of the powders.
4- In caption of Fig. 5, you should sperate the conditions with parenthesis. In the current way it looks like an equation.
We have sperated the conditions with parenthesis.
Line 197. Figure 5. XRD patterns of Ti-Al powders obtained at different energy levels injected into the wires: (1) U0 = 22 кВ; (2) U0 = 25 кВ; (3) U0 = 29 кВ.
5- In 3.3. Ti-Al particle formation; it would be better to explain the phase formation based on/showing phase diagram. Additionally, following statement should be revised seems not clear. “In the case of sample 1 … depleted in aluminum”.
The chapter 3.3 has been redrafted totally to clarify the statement on the formation process of the Al-Ti particles.
Lines 203-238. The mechanism of particle formation under conditions of the simultaneous electrical explosion of two wires of different metals is determined by the phase state of the explosion products. In the case of the electrical explosion of metals with a high melting point and electrical resistivity (Fe, Ni, Ti, Mo, W), the large part of the explosion products is in the state of liquid metal droplets of micron and submicron sizes [23]. In the case of the electrical explosion of metals with a low melting point and electrical resistivity (Ag, Cu, Al), the explosion products of wires are represented by a homogeneous mixture of liquid metal clusters and weakly ionized plasma [23,26]. When bimetallic nanoparticles Al-Cu, Al-Ag are obtained using the simulateneous electric explosion of two wires, homogeneous mixing of the explosion products occurs. Under such conditions, the ratio (in at.%) of metals in a nanoparticle corresponds to the ratio of metals in wires. The phase composition of such particles is formed in accordance with the phase diagram of binary systems [20,27].
The use of the simulateneous electric explosion of metal wires with high and low electrical resistivity is accompanied by the formation of a complex phase composition of the explosion products. Along with weakly ionized plasma and liquid metal clusters, the explosion products will contain liquid droplets of metal with a higher melting point and electrical resistivity. This leads to the formation of particles in the state of a binary melt with different metal ratios in the explosion products: nanosized particles with a metal ratio close to that in the wire and micron/submicron particles with a higher content of metal with high electrical resistivity. This feature of the phase state of the metal explosion products with high and low electrical resistivity leads to the formation of a more complex phase composition of particles that does not correspond to the phase diagram of binary systems. These regularities of the phase formation were observed on the Ni-Al samples in [28, 29].
The EETW products of titanium and aluminum wires will contain micron and submicron titanium particles. Upon coalescence of the explosion products of titanium and aluminum wires, micron titanium particles will be alloyed with aluminum, which creates conditions for the formation of α-Ti and α2-Ti3Al phases. The ratio of metals in nanosized particles is close to that of metals in wires, which creates conditions for the formation of nanoparticles with a γ-TiAl structure. An increase in the energy injected into the wires in the investigated range U0 = 22 - 29 kV leads to a decrease in the number and size of micron titanium droplets, as a result, the content of α-Ti and α2-Ti3Al phases in the EETW products decreases. A decrease in the content of micron titanium particles can also be achieved by additional heating of the expanding EEW products at the arc stage of the process [30].
We have added four references:
- M. Romanova, G. V. Ivanenkov, A. R. Mingaleev, A. E. Ter-Oganesyan, I. N. Tilikin, T. A. Shelkovenko, and S. A. Pikuz, On the phase state of thin silver wire cores during a fast electric explosion. Physics of Plasmas. 25 (2018) 112704. https://doi.org/10.1063/1.5052549.
- Pervikov, M. Lerner, Mechanism of the formation of the structure and phase state of binary metallic nanoparticles obtained by the electric explosion of two wires made of different metals. Current Applied Physics. 17 (2017) 1494 - 1500. https://doi.org/10.1016/j.cap.2017.08.017.
- Ishihara, T. Koishi, T. Orikawa, H. Suematsu, T. Nakayama, T. Suzuki, K. Niihara, Synthesis of intermetallic NiAl compound nanoparticles by pulsed wire discharge of twisted Ni and Al wires. Intermetallics. 23 (2012) 134-142. https://doi.org/10.1016/j.intermet.2011.12.026.
- Abraham, H. Nie, M. Schoenitz, A. Vorozhtsov, M. Lerner, A. Pervikov, N. Rodkevich, E. Dreizin, Bimetal Al–Ni nano-powders for energetic formulations. Combustion and Flame. 173 (2016) 179-186. https://doi.org/10.1016/j.combustflame.2016.08.015.
6- In equation (4) temperature T was not defined.
The parameter “temperature T” has been defined in the declaration of the Equation 3 where this parameter was used before.
Line 275. T – absolute temperature.
7- On page 10/12, after discussion on the oxygen content of produced particles it is required to add the following statement with related references to show the positive effect of oxygen in strengthening of Ti alloys. “However, it is difficult to eliminate the oxygen during fabrication of Ti powders. Additionally, the existance of small amount of oxygen results in strengthening of Ti alloys”.
[Ref] Strengthening evaluation and high-temperature behavior of Ti–Fe–O–Cu–Si alloy
[Ref] Microstructure globularization of high oxygen concentration dual-phase extruded Ti alloys via powder metallurgy route
Thanks for the very important suggestion.
We have completed the text and added two references:
Lines 332-334. “However, it is difficult to eliminate the oxygen during fabrication of Ti powders. Additionally, the existence of small amount of oxygen results in strengthening of Ti alloys”.
- A. Bahador, J. Umeda, R. Yamanoglu, T. A. Abu Bakar, K. Kondoh, Strengthening evaluation and high-temperature behavior of Ti–Fe–O–Cu–Si alloy, Mater. Sci. Eng. A. 800 (2021) 140324. https://doi.org/10.1016/j.msea.2020.140324.
- A. Bahador, J. Umeda, H. Ghandvar, T. A. Abu Bakar, R. Yamanoglu, A. Issariyapat, K. Kondoh, Microstructure globularization of high oxygen concentration dual-phase extruded Ti alloys via powder metallurgy route, Mater. Charact. 172 (2021) 110855. https://doi.org/10.1016/j.matchar.2020.110855
8- In XRD evaluation of sintered powders at 1000 C Fig. 9, why you did not identify γ-TiAl phase while peaks are visible? In addition, Ti3.3Al or Ti3Al?
Line 347. Figure 9. We have revised XRD spectra of sintered powders at 1000 °C and identified γ-TiAl, α2-Ti3Al and TiAl2 phases.
Reviewer 2 Report
The paper reports a synthesis method to prepare Ti-Al intermetallic particles via electrical explosion of twisted titanium and aluminum wires. Some authors of this paper have been publishing in this field (e.g. 20, 21, 23 and 25). This study addresses a very interesting research topic that falls within the scope of this journal. The paper is well-structured and written in very good English language. The topic of this article is addressed in an appropriate, consistent, and thorough way. Furthermore, the results are presented and interpreted appropriately, so that all conclusions are sound and justified. Hence the reviewer recommends the publication of this article in this current version.
Author Response
The paper reports a synthesis method to prepare Ti-Al intermetallic particles via electrical explosion of twisted titanium and aluminum wires. Some authors of this paper have been publishing in this field (e.g. 20, 21, 23 and 25). This study addresses a very interesting research topic that falls within the scope of this journal. The paper is well-structured and written in very good English language. The topic of this article is addressed in an appropriate, consistent, and thorough way. Furthermore, the results are presented and interpreted appropriately, so that all conclusions are sound and justified. Hence the reviewer recommends the publication of this article in this current version.
Dear Reviewer!
Authors are thankful to you for the comment. We have made careful modifications to the original manuscript, including English language. All changes made to the text are in blue color.
Reviewer 3 Report
It is a correct technological manuscript about the electrical explosion synthesis, oxidation and sintering of Ti-Al intermetallic powders. Nevertheless, this manuscript needs major revision.
Comments:
Has the reproducibility of the results obtained been analyzed? The processing conditions are very specific and dispersion can occur in the results.
To what extent has the homogeneity of the compound produced been proven?
XRD analysis: The authors should provide the percentage of each phase detected in the XRD diffraction patterns.
Likewise, sometimes oxides are formed. There are undesired?
There are values as the average particle size and phase composition (table 2) that’s needs the addition of the statistical error or dispersion.
Figure 3 graphs are so small. Letters and symbols size …….
The authors should unify the format of units in the graphs ( , unit; (unit); …) taking into account the format suggested by the journal.
Author Response
Dear Reviewer!
Thank you for your valuable comments on our manuscript. In the revised version of the manuscript, all your comments and suggestions were considered and carefully addressed.
Please see the attachment.
Author Response File: 
Author Response.pdf
Round 2
Reviewer 3 Report
The authors modify the manuscript taking into account the comments of the referee.
The discussion of the experimental results.
Thus, the manuscript has been significantly improved and now warrants publication in Metals.
