Feasibility Study on Deposition of Tribaloy T800 on Cobalt-Based L605 Using Micro-Laser-Aided Additive Manufacturing
Round 1
Reviewer 1 Report
Review of the manuscript "Feasibility Study on deposition of Tribaloy T800 on cobalt-based L605 Using Micro-Laser Aided Additive Manufacturing".
The manuscript deals with the deposition of Cobalt-based Triballoy T800 on cobalt-based L605 plate using micro-LAAM.
The manuscript is interesting, the topic novel. English acceptable.
It can be accepted for publication after the following minor revisions:
Line 37 "has" space "very";
Table 1 and 2: please specify wt% or at%.
Table 3: speed, not velocity
Microhardness: please specify the applied load.
Author Response
Dear Reviewer,
Many thanks for your insightful comments. Please find our point to point response to your comments as follows. We have revised our manuscript accordingly.
1. Line 37 "has" space "very";
Response: Thanks a lot for pointing out this typo. We have corrected it in the manuscript.
2. Table 1 and 2: please specify wt% or at%.
Response: Thanks a lot for the comment. Table 1 and 2 showed the chemical composition in weight percentage (wt%). The information has been added to the tables.
3. Table 3: speed, not velocity
Response: Thanks a lot. It has been revised.
4. Microhardness: please specify the applied load.
Response: Thanks a lot. The applied load is 100 grams. It has been added in the manuscript.
Best Wishes,
Guijun Bi
Reviewer 2 Report
This is an interesting article on some of the issues involved in the deposition of tribaloy T800 on cobalt-based L605. The paper focuses on the study of microhardness, microstructure of the resulting material, roughness, porosity and non-cracking when it is a single layer.
A subsequent analysis of the behaviour of the assembly against possible fatigue failure is lacking, since having a harder surface layer may result in worse fatigue behaviour. You should add some discussion in this regard and on the possible embrittlement or not of the assembly at high temperatures.
Please correct typo in line 37 "hasvery"
Author Response
Dear Reviewer,
Many thanks for your valuable comments. Please find our point to point response to your comments as follows. We have revised our manuscript accordingly.
- A subsequent analysis of the behaviour of the assembly against possible fatigue failure is lacking, since having a harder surface layer may result in worse fatigue behaviour. You should add some discussion in this regard and on the possible embrittlement or not of the assembly at high temperatures.
Response: Thanks a lot for your comment. The following discussion has been added to the manuscript section 3.4.
“Furthermore, Tribaloy T800 coating is mainly applied to aeroengine swirler, combustion chamber, etc., which directly contact with high temperature gas. Although no heavy mechanical load applied, the high hardness of the deposited coating may cause the degradation of the fatigue property during the high temperature operation of the parts. Hence, fatigue behaviour of the deposited Tribaloy T800 coating needs to be investigated in future study.”
- Please correct typo in line 37 "hasvery"
Response: Thanks a lot for your comment. We have corrected this typo in the manuscript.
Best Wishes,
Guijun Bi
Reviewer 3 Report
This is a very nice work -congratulations. I have one point, which should be improved. Fig. 2, 5 and 10 shown the fusion line, which is a sketch. Consequently, the measurement of the thickness is only approximately, therefore this should be mentioned. Could you please comment how you obtain this line.
Author Response
Dear Reviewer,
Many thanks for your insightful comments. Please find our response to your comments as follows. We have revised our manuscript accordingly.
- I have one point, which should be improved. Fig. 2, 5 and 10 shown the fusion line, which is a sketch. Consequently, the measurement of the thickness is only approximately, therefore this should be mentioned. Could you please comment how you obtain this line.
Response: Thanks a lot for your comments. The definition “fusion line” used in the figures is not proper. It should be the substrate surface, which can be easily identified from the physical sample. It has been revised in the manuscript.
Best Wishes,
Guijun Bi
Reviewer 4 Report
The authors of : Feasibility Study on deposition of Tribaloy T800 on cobalt-based L605 Using Micro-Laser Aided Additive Manufacturing paper present some new and interesting results using L-AAM technique for some materials with a high industrial interest. However few modifications and comments are necessary to improve the paper for a possible publication:
L10: better explanation of sound integrity of the deposited layer : please provide more details
L25: re-phrase the sentence: The 25 cobalt-based L605 subjects to abrasion during the operation of the equipment.
L41: boning or bonding ?
L63: remove the phrase : The micro-hardness and micro-structure were 63 tested and analyzed.
L66: develop the sentence : Figure 1 shows the experimental set-up for this study.
L76: how was the chemical composition determined ? what technique or equipment ? how many determinations were made ?, what is the detector/equipment error , St dev of the average values etc. or provide a reference
L84: explain IPA
L97: what is A2 solution ? (struers ?)
L108: how was the fusion line established ? it is not clear from the figure
L125: how many measurements were made ? is it 8 um an average value ? can you mark the measured area in figure 3 ?
L135: what is Ttibaloy ?
L135: how was the Fusion line established ?
L138: delete one the
L183: grain structure measurements were performed ? give a reference for : fine
L198: provide a reference (or more) for paragraph: For Tribaloy T800, the presence of Laves phases in a large quantity guarantees high hardness and wear resistance, but a high content of this brittle phase was simultaneously a drawback, since it favored the brittle crack formation and propagation. Additionally, when multilayer deposition was performed by micro-laser aided additive manufacturing, the tendency for thermal cracking to develop significantly increases due to the increased internal residual stress. Therefore, when the number of deposited layers reached to three, under the simultaneous action of brittle phase and high residual stress, obvious cracks were formed in the deposition layer. For multiple-layer deposition with increased thickness, the process needs to be carefully developed to eliminate the cracks.
better structure of the conclusions is necessary
L222: further study concerning what ? please fill the idea
Author Response
Dear Reviewer,
Many thanks for your insightful comments. Please find our point to point response to your comments as follows. We have revised our manuscript accordingly.
- L10: better explanation of sound integrity of the deposited layer: please provide more details
Response: Thanks a lot for the comment. The sound integrity of the deposited layer mean that the deposited layer should have smooth surface, low porosity and no cracks.
L25: re-phrase the sentence: The cobalt-based L605 subjects to abrasion during the operation of the equipment.
Response: Thanks a lot for the comment. We have changed this sentence to “The parts made of cobalt-based L605 subject to abrasion during the operation.”
L41: boning or bonding?
Response: Thanks a lot for pointing out this typo. It has been revised in the manuscript.
L63: remove the phrase: The micro-hardness and micro-structure were 63 tested and analyzed.
Response: thanks a lot. We have removed this phrase.
L66: develop the sentence: Figure 1 shows the experimental set-up for this study.
Response: thanks a lot for the suggestion. We have changed this sentence to “Figure 1 shows the experimental set-up used in this study.
L76: how was the chemical composition determined? what technique or equipment? how many determinations were made? what is the detector/equipment error, St dev of the average values etc. or provide a reference
Response: Thanks a lot for the comments. The chemical composition data are from the material suppliers. The information has been added in the manuscript.
L84: explain IPA
Response: Thanks a lot. IPA is the isopropyl alcohol. It has been revised in the manuscript.
L97: what is A2 solution? (struers?)
Response: Many thanks for the comment. The etchant used was a solution with 25ml water, 25 ml acetic acid and 50 ml HNO3. Furthermore, electrolytic etching was also conducted using a 1.5 V direct current power supply and stainless-steel electrodes in a solution of 10 ml nitric acid, 10 ml hydrogen peroxide, 100 ml oxalic acid. It has been revised in the manuscript.
L108: how was the fusion line established? it is not clear from the figure
Response: Thanks a lot for the comment. The definition “fusion line” used is not proper. It should be the substrate surface, which can be easily identified from the physical sample. It has been revised in the manuscript.
L125: how many measurements were made? is it 8 um an average value? can you mark the measured area in figure 3?
Response: Thanks a lot for the comments. Three measurements were conducted across the laser scanning direction of the last layer, as shown in Figure 3. Figure 4 shows the roughness profile of one measurement. The average surface roughness (Ra) from the three measurements of the deposited sample was only 8 μm. Please see the revisions in section 3.2 of the manuscript.
L135: what is Ttibaloy?
Response: Very sorry for the mistake. We got the wrong spelling of the word. It should be Tribaloy. It has been revised in Figure 5.
L135: how was the Fusion line established?
Response: thanks a lot for the comment. After etching, the interface between the deposited material and the base material is very clear. This interface is defined as “fusion line”.
L138: delete one the
Response: Many thanks. We have deleted it in the manuscript.
L183: grain structure measurements were performed? give a reference for: fine
Response: Thanks a lot for the comment. The grain structure was measured using a software integrated with the optical microscope. The average grain size is smaller than 20 μm.It has been added in section 3.3.
L198: provide a reference (or more) for paragraph: For Tribaloy T800, the presence of Laves phases in a large quantity guarantees high hardness and wear resistance, but a high content of this brittle phase was simultaneously a drawback, since it favored the brittle crack formation and propagation. Additionally, when multilayer deposition was performed by micro-laser aided additive manufacturing, the tendency for thermal cracking to develop significantly increases due to the increased internal residual stress. Therefore, when the number of deposited layers reached to three, under the simultaneous action of brittle phase and high residual stress, obvious cracks were formed in the deposition layer. For multiple-layer deposition with increased thickness, the process needs to be carefully developed to eliminate the cracks.
better structure of the conclusions is necessary
Response: Thanks a lot for the suggestion. Reference 15 has been added. The conclusion has been revised.
L222: further study concerning what? please fill the idea
Response: Thanks a lot for your comment. The following information has been added to the discussion section: As discussed previously, cracking is the major issue for multiple-layer deposition of Tribaloy T800. Hence, further study is necessary to develop the micro-LAAM process, aiming to minimize internal residual stress and the resultant tendency for thermal cracking. High temperature fatigue behaviour is also necessary to be investigated.
Best Wishes,
Guijun Bi
Round 2
Reviewer 4 Report
Publish in the current form
