Influence of Powder Mass Flow Rates on Wear Resistance and Impact Toughness of Inconel 718 Surface Coatings
Mehdi Shakourian-Fard
Round 1
Reviewer 1 Report
One of the reasons hindering the implementation of the laser cladding process is the formation of cracks in the deposited layers. This type of defect is one of the most common. As a result of the formation of cracks in coatings, the fatigue strength of parts is reduced by more than 10-20 times, which can cause premature destruction and failure of the product. In the article, the authors studied 12 different powder feed rates and obtained the optimal parameters of the laser surfacing process when repairing parts made of 27SiMn steel with Inconel 718 powder. The results obtained are important for science and practice. There are only a few questions:
1. In Fig. Figure 5 shows the "Impact toughness" values. To obtain them, specimens with a V-shaped cut were used. Why didn't the authors designate Impact toughness as KCV? Look, for example: https://link.springer.com/article/10.1007/s11003-013-9558-6. I also propose to add this article to the literature analysis,in the Introductory part of the article.
2. Impact toughness, were studied by the authors in the structurally inhomogeneous zone of the deposited metal. I suggest showing the range of scatter of impact toughness parameters.
3. In Fig. 10 shows the mechanisms of specimens fracture. I propose to additionally show the scheme and designate the studied areas. An example for this scheme can be found in Fig. 5, the article recommended in item 1.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The submitted paper is very interesting dealing with the effect of powder delivery speeds to wear resistance and impact toughness for Inconel 718 surfacing coatings. The applied characterization methods are well-established and the conclusions are supported by the experimental results. Some critical remarks are the followings:
i) Have the authors noticed any change of the coating brittleness when the film hardness gets in maximum value? Impact test results can’t show it.
ii) Have the authors investigated the effect of the speed on substrate properties? This is significant especially when the coated parts are used in applications with heavy loads.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
In this study, the authors investigate the influence of powder delivery speed on the coating properties of Inconel718 cladding on 27SiMn steel surface. The cross-sectional microstructure, X-ray diffraction patterns, micro-hardness distribution, friction and wear properties, impact properties, and fracture morphology of the cladding layers have been analyzed at different powder delivery speeds. In my opinion the topic is relevant, the investigation is satisfactory and the manuscript well written. My question is: what is the effect of powder delivery speeds on the porosity property of Inconel718 cladding on 27SiMn steel surface? Furthermore some of grammatical mistakes are observed as follow, which should be addresses throughout the manuscript text:
Introduction: - Introduction: the effect the powder delivery speed→ the effect of powder delivery speed
-Page 3: were polished, polished, and etched→ were polished and etched
- page 9: the fused coating first increase→ the fused coating first increases
- page 9: then decrease as the powder → then decreases as the powder
- page 10 : the coating first increase→ the coating first increases
-page 10: then decrease with the increase of → then decreases with the increase of
Introduction: - Introduction: the effect the powder delivery speed→ the effect of powder delivery speed
-Page 3: were polished, polished, and etched→ were polished and etched
- page 9: the fused coating first increase→ the fused coating first increases
- page 9: then decrease as the powder → then decreases as the powder
- page 10 : the coating first increase→ the coating first increases
-page 10: then decrease with the increase of → then decreases with the increase of
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The submitted paper can be accepted for publication.
Author Response
Thank you to the reviewer for their suggestions.
