Determining Relevant 3D Roughness Parameters for Sandblasted Surfaces: A Methodological Approach

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript presents a well-structured and methodologically rigorous study focused on identifying relevant 3D roughness parameters for characterizing sandblasted Ti-6Al-4V surfaces, with clear implications for industrial optimization—particularly in biomedical applications. However, some modifications are suggested to improve the paper. The authors should address the below comments carefully and incorporate the changes in the revised manuscript.

1. The introduction highlights Ti-6Al-4V as the test material for biomedical applications but lacks sufficient explanation of why this alloy’s surface roughness is critical for biomedical scenarios. It is recommended to supplement specific requirements of biomedical implants for surface texture (e.g., optimal roughness ranges for cell adhesion) and clarify gaps in existing studies on Ti-6Al-4V sandblasted surface characterization.
2. The polishing step (320–1200 grit) is described, but the authors should specify the polishing pressure, speed, and duration, as these parameters can affect the initial surface roughness. Reporting the initial Sa value of polished Ti-6Al-4V (before sandblasting) would also help contextualize the magnitude of roughness changes induced by sandblasting.
3. The study thoroughly summarizes experimental data (e.g., roughness values) and constructs corresponding mathematical models. However, the underlying material removal mechanisms and the evolution of surface microtopography are not sufficiently addressed. Adding analysis to elucidate these points would be valuable.
4. The parameters and pictures of sandblasting equipment should be supplemented.
5. The representation of error bars in Figure B1 and other figures is insufficiently clear. Besides, error bars denote the standard deviation of the data; therefore, it is necessary to confirm whether the error bars in the current images are accurate.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Abstract

1. Makes no sense to include all the R^2 values in the abstract.
2. The sentence "Using five sandblasting types at different pressures..." is misleading. The abstract must clarify that there is only one material (corundum) with different sizes. Moreover, it is important to specify that irregular shaped particles are used.

Introduction

3. The authors provide references that demonstrate the interest of sandblasting process in different sectors. Nevertheless, the authors should provide and discuss the previous findings regarding the dependence of roughness parameters on sandblasting operational parameters.

Materials and methods

4. The authors must describe completely the experimental device used for sandblasting. The pressure alone does not to reproduce the experimental conditions (it is device dependent). The authors must specify the geometry and materials of the employed nozzle, in addition to the exact point where the air pressure is measured.

5. Also, the processing conditions must be fully specified. How long is the surface processed? The powder stream is kept static with respect of the surface or it is scanned along the titanium alloy surface. 

6. Please explain what means "associated grit size". It is suggested to provide the size ranges of each type, ideally the size distribution.

7. As the paper main purpose is to analyse the topography of modified surfaces, it is suggested to specify all the image processing conditions (levelling, filters, etc.).

8. Check spelling in line 125 (flat plan or flat plane).

Results

9. The authors claim at the end of the introduction that "By enabling a finer adjustment of sandblasting parameters according to the desired functional properties of the final product, the methodology developed this study contributes to the optimization of surface engineering processes". Nevertheless, the authors does not bridge the gap between the sandblasting operation parameters and the optimal roughness parameters for Ti-6A1-4V alloy surfaces and specific applications. Without this information, the paper loses interest. The authors must make an effort to analyse what roughness conditions are optimal for determinate applications and relate that conditions to the operational parameters D, P. This point is very important to increase interest of the research.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf