Phase Composition, Nanohardness and Young’s Modulus in Ti-Fe Alloys after Heat Treatment and High Pressure Torsion

Round 1

Reviewer 1 Report

The paper presents a study on Phase composition, nanohardness and Young's modulus in Ti-Fe alloys after heat treatment and high pressure torsion. The work presents quite complete results but some changes must be made to be considered for publication.

Abstract: The abstract should be revised as authors should avoid using "we studied..." and use it several times in the abstract. They must also rectify the word "Aftr".

Introduction: The introduction should be enlarged showing a wider background.

Discussion: The version I have doesn't show the number of lines, but on page 7 when the authors are talking about grains, @ symbols appear.
When the authors present the HV hardness, they must present the load used in accordance with the standard. For the temperature I also think the authors should leave space between the digit and the unit as they for everything else.

Author Response

Reviewer 1

 

The paper presents a study on Phase composition, nanohardness and Young's modulus in Ti-Fe alloys after heat treatment and high pressure torsion. The work presents quite complete results but some changes must be made to be considered for publication.

Abstract: The abstract should be revised as authors should avoid using "we studied..." and use it several times in the abstract. They must also rectify the word "Aftr".

We revised the abstract accordingly

Introduction: The introduction should be enlarged showing a wider background.

We enlarged the introduction showing a wider background

 

Discussion: The version I have doesn't show the number of lines, but on page 7 when the authors are talking about grains, @ symbols appear.

We removed the @ symbols

When the authors present the HV hardness, they must present the load used in accordance with the standard.

The nanohardness has been measured at P_max = 200 mN. We added this value into Materials and Methods section.

For the temperature I also think the authors should leave space between the digit and the unit as they for everything else.

We inserted space the digit and the unit for the temperature

Author Response File: Author Response.pdf

Reviewer 2 Report

"The peaks in XRD patterns before HPT are narrow
because of large grains in the samples after annealing." Do you mean high crystallinity? 

Author Response

Reviewer 2

 

"The peaks in XRD patterns before HPT are narrow
because of large grains in the samples after annealing." Do you mean high crystallinity? 

 

Yes. Now these sentences are look in the following way:

“The peaks in XRD patterns before HPT are narrow. It is due to the high crystallinity of the samples and large grain size in the samples after annealing.”

Author Response File: Author Response.pdf

Reviewer 3 Report

This work gives some interesting results of TiFe alloy properties. The manuscript is quite well organized, results are good presented, but some corrections are needed before publishing

 

1. Please add some details to the statement “The alloys were manufactured ... by the levitation method ...“
2. Give more details (lattice structure) on omega phase. Why it appears after HPT?
3. Please define the difference between “nanohardness“ microhardness and „hardness“ as the last sentence of Discussion section talks about „micro/nanohardness of the material“.
4. Conclusions are trivial. It would be nice to formulate scientific conclusions from the quantitative results of the work.
5. In the introduction is stated that “... to study two series of titanium‐iron samples...”. But I cannot see two series, I see 4 different samples with different Fe concentrations, annealed at two different temperatures. Two series are not mentioned in 2. Materials and Methods? Please explain or change this statement. The same in the introduction “We studied two series of...”

 

6. Mistake in the introduction “Aftr HPT, ...”

 

7. References, remove the text from the template

 

8. In Fig 1 some peaks are marked as alga/beta/omega. What does it mean? Please explain.

Author Response

Reviewer 3

 

This work gives some interesting results of TiFe alloy properties. The manuscript is quite well organized, results are good presented, but some corrections are needed before publishing

 

1. Please add some details to the statement “The alloys were manufactured ... by the levitation method ...“

We added the following explanation:

In this method the molten metal levitates in a so-called cold crucible, consisting of a circular set of vertically standing, water-cooled copper tubes. Around the cold crucible is a water-cooled copper induction coil, which excites a powerful magnetic field with a supersonic frequency in the cold crucible. Foucault eddy currents are induced in the molten metal, which cause intense heating of the metal, up to its melting. At the same time, eddy currents create a counter magnetic field around the melt, which interacts with the primary field and generates Lorentz forces, which allow a liquid metal bath to float in a vacuum or inert atmosphere without touching the walls of a cold crucible.

 

1. Give more details (lattice structure) on omega phase. Why it appears after HPT?

We added the respective explanations at the beginning of Section 4. Discussion

1. Please define the difference between “nanohardness“ microhardness and „hardness“ as the last sentence of Discussion section talks about „micro/nanohardness of the material“.

We discussed the between “nanohardness“ microhardness and „hardness“ as follows:

One has to underline here the difference between nano- and microhardness. When one says "hardness" of a material, one means the property of the material to resist the penetration of a harder material, i.e. indenter. It is necessary to clearly distinguish between the microhardness and nanohardness of the material. The "nano" prefix reflects the ability of the insruments to measure the displacement of the indenter with a nanometer resolution and operate in the load range from tens to hundreds of nanonewton to about 10 N. Nanoindentation is realized during tests when the indenter penetration depth h is below 200 nm, microindentation is performed by an indentation force P up to 2 N at h> 0.2 μm, and macroindentation is performed by a force P from 2 N to 30 kN. The value of nanohardness can differ significantly from the microhardness for the same material [77-79]. In our work, the nanohardness of the material was measured at P_max = 200 mN.

 

1. Conclusions are trivial. It would be nice to formulate scientific conclusions from the quantitative results of the work.

We improved the conclusions

 

1. In the introduction is stated that “... to study two series of titanium‐iron samples...”. But I cannot see two series, I see 4 different samples with different Fe concentrations, annealed at two different temperatures. Two series are not mentioned in 2. Materials and Methods? Please explain or change this statement. The same in the introduction “We studied two series of...”

We changed this statement and now everywhere mentioned four different Ti-Fe alloys

 Mistake in the introduction “Aftr HPT, ...”

We corrected it

 References, remove the text from the template

We removed the text from the template in References

 In Fig 1 some peaks are marked as alga/beta/omega. What does it mean? Please explain.

We added the following explanation:

“After exposure to HPT, the peaks in the XRD patterns become wide and "blurred". As a result, one, two or even three closely lying XRD peaks corresponding to different phases can fall under such a "blurred" peak. The phase analysis and calculation of the lattice parameters were carried out using the PowderCell for Windows Version 2.4.08.03.2000 program (Werner Kraus & Gert Nolze, BAM Berlin). The program distinguishes all phases and closely lying lines of different phases. The scale of the drawings does not allow us to make more inscriptions and preserve the readability of the text, therefore we used such a system for describing peaks.”

 

 

 

Round 2

Reviewer 1 Report

The manuscript was changed according to the comments.