Optimization of Measurement Area Selection for Accurate 3D Surface Topography Characterization in High-Feed Tangential Turning of 42CrMo4 Alloy Steel
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript focus on the machined surface topography through 3D surface roughness measurements. The effect of measurement area selection on key roughness parameters was examined. The topic selection of this manuscript is of limited significance and lacks substantial innovation.
- The study investigates the impact of measurement area selection on 3D surface roughness parameters, a topic already addressed in foundational standards (e.g., ISO 25178) and prior research (e.g., Refs. [14,18]). The key finding that "measurement length exceeding 5 mm stabilizes parameters" merely replicates established conclusions without proposing innovative models or techniques. The research fails to advance the field by introducing new theoretical frameworks or practical methodologies for tangential turning surface characterization.
- By limiting experiments to 42CrMo4 alloy steel, the study neglects to validate measurement strategies across diverse materials (e.g., aluminum, titanium alloys) that exhibit distinct machining-induced surface topographies. Additionally, the process parameter range is narrow (cutting speed: 200–300 m/min, feed rate: 0.6–1.0 mm/rev), excluding high-speed machining (e.g., >500 m/min) and micro-feed scenarios, which restricts the generalizability of conclusions to industrial applications.
- The reliance on a single profilometer (AltiSurf 520) without cross-verification against white-light interferometers or stylus profilometers introduces uncertainties in data consistency. Furthermore, the arbitrary adoption of a 2.5 mm cutoff value, lacks experimental justification—varying cutoff values (e.g., 1.0 mm, 5.0 mm) should be tested to assess their impact on parameter stability, as required by ISO guidelines.
- While the study reports roughness parameter trends, it fails to link these metrics to practical component functionalities. For instance, parameters like Ssk and Sku (–) are discussed solely in numerical terms, without interpreting their implications for tribological performance or mechanical contact behavior. This limits the research’s utility for engineering design.
- The abstract states a "minimum sampling scale of ~5 mm", conflicting with the "5.5–6.0 mm" in the text, undermining the study’s rigor. Additionally, the discussion section lacks comparative analysis with similar works, failing to clarify how this research differentiates from existing studies. Such omissions obscure the study’s academic positioning.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsAfter preparing the below comments, I noticed that this work heavily overlaps with the (better-written) ref [24] by the same author (https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/14515/6162). I am not clear what the value of this new article is!
General comments:
- Article is too long for the current content. Should be made more concise. There is too much repetition of ‘navigation’ comments at the start of sections.
- No need to ‘preview’ the outcomes (except in the abstract). Wait for the reader to get there!
Specific comments:
- Abstract is long, but lacks precise summary statements about specific conclusions of the paper.
- The introduction is too general and unfocussed. I recommend citing well-known review paper(s) then make the rest of the introduction more focussed. This is a metrology journal, so more reader knowledge can be assumed.
- Agree that the profile texture standards provide clear default filter bandwidths whilst ISO 25178 does not (or not as clearly. But:
- Even the defaults might not be appropriate for a special type of surface
- ISO 25178-3 does provide a note (I think under ‘S-L surface’ definition) that the L-filter is typically chosen as 5x the largest length scale of interest.
- ‘Tangential turning’ is more likely to be a new concept to the reader. Please provide diagram(s) of the process/geometry.
- The periodic waviness structures are important. Can you show some examples of these surfaces? Is there a direction to the structure? Does it form ‘lanes’ with each cutter pass? Is there a dominant spatial wavelength range we can focus attention on?
- I think you started the work using R-parameters then switched to S-parameters, right? Change e.g. ‘evaluation length’ to ‘evaluation area [width]’
- Choice of cutting parameters. You have explained your choices, which is good. But I would clearly separate the discussion about the surface preparation – and how representative they are – from the later measurement and analysis. The metrology reader only wants to know how well these examples cover the potential range of surfaces from this application.
- Please provide more detail about the measurements and initial topography preparation:
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- Measurement principle of the Altisurf, and any information about its metrological characteristics, resolution, NA…
- XY point spacing on the surface (I think the Altisurf is a chromatic confocal point sensor with an XY scanner, right?)
- Was the maximum area restricted by the capabilities of the instrument? Would you have included a larger area if possible?
- You say that the system provides detailed analysis, then immediately talk about using Altimap, which seems separate. Please remove the marketing information!
- Please show the complete high-resolution topography map that you extract areas from. This is important to understand the next steps. You can remove the ‘form’ as appropriate.
- Did you take enough initial topography maps to be confident about the conclusions?
- Area extraction study
- I think AltiMap is based on DigitalSurf’s MountainsMap, right? We use this a lot too.
- Please use ‘ISO 25178’ language for operations e.g. “Zoom” à “Area extraction (‘zoom operation’)”, or “F-operation” for form removal.
- It is possible to extract and analyse a surface that is larger than the L-filter, as long as this is described.
- What about extracting multiple areas then calculating statistics?
- When you introduce the S-parameters (and please call them S-parameters), I recommend you start with the symbols (e.g. Sq) and use these always (including the tables and figures).
- One big question: is an areal measurement actually the best plan for routine measurement? If the texture ‘follows’ the cutting tool around the surface, then a helical profile path might be best! In fact, the chromatic confocal probe in the Altisurf is ideal for this – a stand-alone probe could even sit on the machine tool while the machine motion is ‘replayed’, so you get perfect ‘form removal’!
- Have you heard of formal multi-scale analysis e.g. https://www.sciencedirect.com/science/article/pii/S0007850618301586?
- The results tables are not helpful. I recommend you show e.g. figure 2 earlier instead.
- For figure 2 etc. Why not use a common vertical axis for all plots, and allow that exist to ‘stretch’ for clarity?
- I don’t understand the purpose of the ‘incremental relative change’ figures.
- When you analyse the parameters, you start to talk about how the machining process affects the surface. I recommend discussing this earlier, when you show the ‘complete’ topography maps.
- I struggle to see any clear patterns in figure 2 etc. I think you might need to go to even smaller areas (or rather, keep a large area but reduce the L-filter cutoff below 2.5 mm). I think this is why your discussion for each parameter is not clear – there is not much to conclude!
- Recommend you take some test profiles across the dominant texture and show how features are affected by filtration (or, better, look at spatial wavelength distribution).
- The ‘comprehensive discussion’ (s4.7) is muddled. Please try to untangle (a) discussion about the machining process from (b) the findings about evaluation area / filtration selection.
- General point: you attempt to discuss selection of evaluation area *size* but you don’t really talk about how to select area *location* on the workpiece (and whether you should have multiple areas, or whether there is any periodic variation with each rotation of the workpiece, or if the ‘chatter’ changes with position along the workpiece).
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authorssee file
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe author has revised the paper in accordance with the reviewers' comments. It is suggested that the paper be further polished and improved.
Author Response
The reviewer’s kind words are appreciated. Further polish and improvement are carried out.
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for your efforts to improve the manuscript. The approach is now much clearer.
I would argue there are better ways to analyse the topography (including by breaking the areal data into profiles along and across the texture). You could also look more into uncertainty and repeatability of the parameter values with position on the parent texture.
There are probably ways to predict the stability of the parameter values. You would normally aim for an integer multiple of the texture period, right?
But because the manuscript is much clearer, I think it is acceptable. Readers can judge the methods, as they would for any manuscript!
Author Response
I am thankful for the comments and suggestions which helped with the improvement of the manuscript. The future research areas mentioned are declared at the end of the conclusions.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe article may be published
Author Response
Thank you for your acceptance of the carried-out corrections.