Shape Accuracy Improvement in Selective Laser-Melted Ti6Al4V Cylindrical Parts by Sliding Friction Diamond Burnishing
Round 1
Reviewer 1 Report
Brief description
Sliding friction diamond burnishing was applied as postprocessing method after additively manufactured metallic test specimens in order to achieve more accurate shape. A five factor, two level full factorial design of experiment was implemented with factors laser power, laser scan speed, burnishing speed, feed and force. Based on the experimental results the authors concluded that burnishing feed has largest main effect to improvement of roundness total and cylindricity.
Recommendations for Authors and a few comments on the article.
1) The article says nothing about the roughness of the surface of the samples. In particular, data on the initial roughness of the samples are not given. Clamping force and burnishing feed have a significant impact on the roughness. Do the roughness reduction after burnishing and the shape accuracy correlate? A small analysis on this issue would be desirable to see in the article.
2) Regression dependences 3-7 contain 8 coefficients with different combinations of 3 factors (main effects, pair and triple interactions). With 8 experiments (Table 2), it is impossible to assess the statistical significance of the model and its coefficients. The coefficient of determination, which is usually used to calculate the adequacy of the regression model will be identical to 1 and therefore not applicable for this case. The number of coefficients and experiments are equal and therefore Fisher's F-test, which is used to determine the statistical accuracy of a model, is meaningless. In this case, it is difficult to reliably assess the influence of factors and their interaction.
3) The authors did not explain how the quantitative estimates of the effects in Tables 4 and 5 were obtained. What are these values? Regression model coefficients?
4) Figure 2 captions require SLM process parameters
Author Response
The enclosed .pdf document contains our answers.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article is very timely. SLM technology is being widely nowadays. The article provides valuable insights and knowledge that can be used in technical practice to process this type of material.
A multifactorial experiment has been carefully prepared and implemented.
In the article, I miss the metallographic structure of the base material and the evaluation of its porosity.
Author Response
The enclosed .pdf document contains our answers.
Reviewer 3 Report
In this paper, the effect of sliding friction diamond burnishing on shape accuracy of SLM Ti6Al4V parts was been studied. However, the present work is not innovative. The introduction and the results parts are not clear to the reader. Moreover, a large number of grammatical errors are present. For instance, “It was also studied how surface roughness improvement of selective laser melted Ti5Al4V parts…”.
Author Response
The enclosed .pdf document contains our answers.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors took into account all the comments of the reviewer. Good luck to them.
Author Response
Thank you very much!
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors have made a revision. However, there are a few points that needs to be modified.
1. In page 1, line 43: Selective laser melted Ti5Al4V parts should be modified to Ti6Al4V parts.
2. The introduction in section 2. Materials and Methods needs to be simplified. The content about section 2.1 Titanium alloy Ti6Al4V and 2.2 Selective laser melting should be added to section 1. Introduction.
Author Response
We have accepted your proposal and corrected the paper.
Author Response File: Author Response.pdf
