## 5 Conclusions  
In this research work, a modified measurement framework is investigated for profile and areal surface texture characterization of as-built additive manufactured components. The investigative framework was applied on surfaces built from four different AM techniques. The following were the key findings from this investigation.  
1. Scanning electron microscope analysis provided a better understanding of the type of surface asperities present in an AM component.
2. The maximum diameter (\(\varphi_{\text{m}}\)) of each type of asperity can be used as a cut-off value for profile and areal surface texture characterization.
3. Changing the \(\lambda_{\text{c}}\) values used for profile surface texture leads to significant percentage deviations in the resulting profile surface texture parameters. Minimum deviations were noticed by reducing the evaluation length. Therefore, if the users experience insufficient sample length for measurement, it is recommended to maintain the \(\lambda_{\text{c}}\) suggested by ISO and compromise the evaluation length.
4. The length and width of the evaluation area for the areal surface texture analysis of AM surface should be five times the selected \(\lambda_{\text{c}}\). If there is an insufficient area to measure, select the length and width of the area to be at least twice the \(\lambda_{\text{c}}\) selected.
5. To characterize the AM surface texture, smaller measurement areas (2 mm \(\times\) 2 mm or even less, but not below the size of large irregularities present) are sufficient.
6. By measuring the size of asperities present on the surface and applying them as \(\lambda_{\text{c}}\), it is possible to analyze the surface texture from short wavelengths (loose particles, partially melted particles) and long wavelengths (balling melts, semi-welded structures, and staircase effect) separately.  
Some of the major challenges and limitations in this work include categorizing the type of surface asperities present in AM components based on visual observation, measurement accuracy of asperities through image analysis, and the percentage transmission of wavelengths in roughness/waviness topography. Notwithstanding the limitations, the above findings address all the questions (in Section 1) arising during AM surface texture measurements. The significance of this study helps to eliminate user speculations on selecting a particular measurement setting for roughness evaluation, improves confidence to select the appropriate measurement area for roughness evaluation, and improves awareness of the changes in the roughness results due to changes in measurement settings. This helps resolve the discrepancies observed while applying standards originally formulated for conventional surfaces on non-uniform AM surfaces. The work performed also proves that the investigated framework can characterize different materials and AM techniques.  
**Author Contributions:** Conceptualization: A.P.N., M.S.V., and P.K.; Methodology: M.S.V., and P.K.; validation, M.S.V., and P.K.; Investigation: A.P.N.; Data curation: A.P.N., M.S.V., and P.K.; Writing--original draft preparation: A.P.N.; Writing--review and editing: M.S.V., and P.K., and S.H.Y.; Supervision: S.H.Y. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Acknowledgments:** This work was performed within the Rolls-Royce@NTU Corporate Lab, a joint university technology center between Nanyang Technological University and Rolls-Royce, with support from the National Research Foundation (NRF) of Singapore. The authors would like to thank the Manufacturing Technologies team at Rolls-Royce@NTU corporate lab, Singapore, for their support and contributions.  
**Conflicts of Interest:** The authors declare no conflict of interest.