AccScience Publishing / MSAM / Volume 5 / Issue 1 / DOI: 10.36922/MSAM025280062
ORIGINAL RESEARCH ARTICLE

On the surface integrity resulting from laser powder bed fusion of Ti6Al4V: Improvements by cavitation abrasive surface finishing

Rohin Petram1† Conall Wisdom1† Alex Montelione1† Cole Nouwens2 Angelina Martinez1 Marqui Silvestre1 Dan Sanders2,3* Mamidala Ramulu2 Dwayne Arola1,2*
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1 Department of Materials Science and Engineering, University of Washington, Seattle, Washington, United States of America
2 Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States of America Sugino Machine Ltd., Toyama, Japan
†These authors contributed equally to this work.
MSAM 2026, 5(1), 025280062 https://doi.org/10.36922/MSAM025280062
Received: 12 July 2025 | Accepted: 15 August 2025 | Published online: 14 October 2025
© 2025 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract

As the manufacturing readiness level of laser powder bed fusion (L-PBF) advances, post-processing has become increasingly important for achieving net-shape components and to enhance surface texture and integrity. Apart from surface roughness, one concern is the unique morphology of printed surfaces with vertical, upskin, and downskin inclinations. In this study, we characterized the surface texture and integrity of L-PBF Ti6Al4V with respect to build orientation. In the as-built condition, the downskin surfaces possessed the highest roughness, the largest effective surface stress concentration(),Ktand the greatest presence of partially melted powder particles fused to the surface. Cavitation abrasive surface finishing (CASF) was adopted to improve surface quality, with consideration of the build orientation. The results indicated that CASF reduced roughness, lowered Kt posed by the surface texture, and introduced compressive residual stress regardless of the build orientation. Downskin surfaces were the most challenging to treat; they exhibited substantially greater Ktthan the other orientations after treatment (>2×) and lower compressive residual stress (50%). More extensive powder coverage of the downskin surfaces appears to shield the underlying substrate from abrasive attack and direct implosion of cavitation bubbles, which are central to the CASF treatment mechanism. The importance of orientation to the effectiveness of CASF treatment is discussed, as well as strategies to overcome this challenge. Overall, downskin surfaces require greater surface treatment intensity or duration to obtain the same degree of improvement.

Graphical abstract
Keywords
Additive manufacturing
Laser powder bed fusion
Post-processing
Residual stress
Roughness
Stress concentration
Surface treatment
Titanium
Funding
The authors gratefully acknowledge that support for this work was provided by the Joint Center for Aerospace Technology Innovation (JCATI) in Washington State. The authors also gratefully acknowledge support for this investigation from The Boeing Company through the Boeing Advanced Research Collaboration and from the Sugino Corporation, Ltd. Part of this work was supported by the Washington Nanofabrication Facility/Molecular Analysis Facility, a National Nanotechnology Coordinated Infrastructure (NNCI) site at the University of Washington with partial support from the National Science Foundation (NNCI-1542101 and NNCI-2025489).
Conflict of interest
Dr. Dan Sanders declares that he is an employee of Sugino Corporation as a chief technical officer, which may be perceived as a conflict.
References
  1. Diegel O, Nordin A, Motte D. A practical guide to design for additive manufacturing. Springer Series in Advanced Manufacturing. Berlin: Springer; 2019. doi: 10.1007/978-981-13-8281-9_2
  2. Galati M, Calignano F, Viccica M, Iuliano L. Additive manufacturing redesigning of metallic parts for high precision machines. Crystals (Basel). 2020;10(3):161. doi: 10.3390/cryst10030161
  3. Zegard T, Paulino GH. Bridging topology optimization and additive manufacturing. Struct Multidiscipl Optim. 2016;53(1):175-192. doi: 10.1007/s00158-015-1274-4
  4. Allen J. An Investigation into the Comparative Costs of Additive Manufacture vs. Machine from Solid for Aero Engine Parts. In: Cost Effective Manufacture via Net-Shape Processing. France: Neuilly-sur-Seine; 2006.
  5. Cabanettes F, Joubert A, Chardon G, et al. Topography of as built surfaces generated in metal additive manufacturing: A multi scale analysis from form to roughness. Precis Eng. 2018;52:249-265. doi: 10.1016/j.precisioneng.2018.01.002
  6. Elambasseril J, Rogers J, Wallbrink C, Munk D, Leary M, Qian M. Laser powder bed fusion additive manufacturing (LPBF-AM): The influence of design features and LPBF variables on surface topography and effect on fatigue properties. Crit Rev Solid State Mater Sci. 2023;48(1):132-168. doi: 10.1080/10408436.2022.2041396
  7. Gomez-Gallegos A, Mandal P, Gonzalez D, Zuelli N, Blackwell P. Studies on titanium alloys for aerospace application. Defect Diffus Forum. 2018;385:419-423. doi: 10.4028/www.scientific.net/DDF.385.419
  8. Williams JC, Boyer RR. Opportunities and issues in the application of titanium alloys for aerospace components. Metals (Basel). 2020;10(6):705. doi: 10.3390/met10060705
  9. Boyer RR. An overview on the use of titanium in the aerospace industry. Mater Sci Eng A. 1996;213(1):103-114. doi: 10.1016/0921-5093(96)10233-1
  10. Singh P, Pungotra H, Kalsi NS. On the characteristics of titanium alloys for the aircraft applications. In: Mater Today: Proceedings. Vol. 4. Netherlands: Elsevier Ltd.; 2017. p. 8971-8982. doi: 10.1016/j.matpr.2017.07.249
  11. Bache MR. Processing titanium alloys for optimum fatigue performance. Int J Fatigue. 1999;21:S105-S111. doi: 10.1016/S0142-1123(99)00061-4
  12. Hosseini S. Fatigue of Ti-6Al-4V. London: IntechOpen; 2012. doi: 10.5772/45753
  13. Novovic D, Dewes RC, Aspinwall DK, Voice W, Bowen P. The effect of machined topography and integrity on fatigue life. Int J Machine Tools Manuf. 2004;44(2):125-134. doi: 10.1016/j.ijmachtools.2003.10.018
  14. Javidi A, Rieger U, Eichlseder W. The effect of machining on the surface integrity and fatigue life. Int J Fatigue. 2008;30(10):2050-2055. doi: 10.1016/j.ijfatigue.2008.01.005
  15. Arola D, Williams CL. Estimating the fatigue stress concentration factor of machined surfaces. Int J Fatigue. 2002;24(9):923-930. doi: 10.1016/S0142-1123(02)00012-9
  16. Arola D, Ramulu M. An Examination of the effects from surface texture on the strength of fiber reinforced plastics. J Compos Mater. 1999;33(2):102-123. doi: 10.1177/002199839903300201
  17. Persson BNJ. Surface roughness-induced stress concentration. Tribol Lett. 2023;71(2):66. doi: 10.1007/s11249-023-01741-4
  18. Ye C, Zhang C, Zhao J, Dong Y. Effects of post-processing on the surface finish, porosity, residual stresses, and fatigue performance of additive manufactured metals: A review. J Mater Eng Perform. 2021;30(9):6407-6425. doi: 10.1007/s11665-021-06021-7
  19. Pegues J, Roach M, Scott Williamson R, Shamsaei N. Surface roughness effects on the fatigue strength of additively manufactured Ti-6Al-4V. Int J Fatigue. 2018;116:543-552. doi: 10.1016/j.ijfatigue.2018.07.013
  20. Vayssette B, Saintier N, Brugger C, Elmay M, Pessard E. Surface roughness of Ti-6Al-4V parts obtained by SLM and EBM: Effect on the high cycle fatigue life. Procedia Eng. 2018;213:89-97. doi: 10.1016/j.proeng.2018.02.010
  21. Singh K, Sadeghi F, Correns M, Blass T. A microstructure based approach to model effects of surface roughness on tensile fatigue. Int J Fatigue. 2019;129:105229. doi: 10.1016/j.ijfatigue.2019.105229
  22. Snyder JC, Thole KA. Understanding laser powder bed fusion surface roughness. J Manuf Sci Eng. 2020;142(7):1-37. doi: 10.1115/1.4046504
  23. Whip B, Sheridan L, Gockel J. The effect of primary processing parameters on surface roughness in laser powder bed additive manufacturing. Int J Adv Manuf Technol. 2019;103(9-12):4411-4422. doi: 10.1007/s00170-019-03716-z
  24. Obilanade D, Dordlofva C, Törlind P. Surface roughness considerations in design for additive manufacturing - a literature review. In: Proceedings of the Design Society. Vol. 1. Cambridge University Press; 2021. p. 2841-2850. doi: 10.1017/pds.2021.545
  25. Khan HM, Karabulut Y, Kitay O, Kaynak Y, Jawahir IS. Influence of the post-processing operations on surface integrity of metal components produced by laser powder bed fusion additive manufacturing: A review. Mach Sci Technol. 2020;25(1):118-176. doi: 10.1080/10910344.2020.1855649
  26. Lu D, Liu Z, Wei X, Chen C, Wang D. Effect of post-processing methods on the surface quality of Ti6Al4V fabricated by laser powder bed fusion. Front Mater. 2023;10:1126749. doi: 10.3389/fmats.2023.1126749
  27. Makhetha WMI, Becker TH, Sacks N. Post-processing framework for as-built LPBF Ti-6Al-4V parts towards meeting industry functional requirements. JOM (1989). 2022;74(3):764-776. doi: 10.1007/s11837-021-05078-y
  28. Triantaphyllou A, Giusca CL, Macaulay GD, et al. Surface texture measurement for additive manufacturing. Surf Topogr Metrol Prop. 2015;3(2):24002. doi: 10.1088/2051-672X/3/2/024002
  29. Covarrubias EE, Eshraghi M. Effect of build angle on surface properties of nickel superalloys processed by selective laser melting. JOM (1989). 2018;70(3):336-342. doi: 10.1007/s11837-017-2706-y
  30. Leach RK, Bourell D, Carmignato S, Donmez A, Senin N, Dewulf W. Geometrical metrology for metal additive manufacturing. CIRP Ann. 2019;68(2):677-700. doi: 10.1016/j.cirp.2019.05.004
  31. Rott S, Ladewig A, Friedberger K, Casper J, Full M, Schleifenbaum JH. Surface roughness in laser powder bed fusion - Interdependency of surface orientation and laser incidence. Add Manuf. 2020;36:101437. doi: 10.1016/j.addma.2020.101437
  32. Shange M, Yadroitsava I, Pityana S, Yadroitsev I, Bester D. Surface morphology characterisation for parts produced by the high speed selective laser melting. IOP Conf Ser Mater Sci Eng. 2019;655(1):12045. doi: 10.1088/1757-899X/655/1/012045
  33. Lizzul L, Bertolini R, Ghiotti A, Bruschi S. Effect of AM-induced anisotropy on the surface integrity of laser powder bed fused Ti6Al4V machined parts. Proc Manuf. 2020;47:505-510. doi: 10.1016/j.promfg.2020.04.149
  34. Metelkova J, Vanmunster L, Haitjema H, Van Hooreweder B. Texture of inclined up-facing surfaces in laser powder bed fusion of metals. Add Manuf. 2021;42:101970. doi: 10.1016/j.addma.2021.101970
  35. Calignano F. Investigation of the accuracy and roughness in the laser powder bed fusion process. Virtual Phys Prototyp. 2018;13(2):97-104. doi: 10.1080/17452759.2018.1426368
  36. Jurg M, Medvedev AE, Yan W, Molotnikov A. Surface improvement of laser powder bed fusion processed Ti6Al4V for fatigue applications. Add Manuf Lett. 2022;3:100070. doi: 10.1016/j.addlet.2022.100070
  37. Soe AN, Sombatmai A, Promoppatum P, Srimaneepong V, Trachoo V, Pandee P. Effect of post-processing treatments on surface roughness and mechanical properties of laser powder bed fusion of Ti-6Al-4V Effect of post-processing treatments on surface roughness and mechanical properties of laser powder bed fusion of Ti-6Al-4V. J Mater Res Technol. 2024;32:3788-3803.
  38. Risposi T, Rusnati L, Patriarca L, Hardaker A, Luczyniec D, Beretta S. Fatigue of Ti6Al4V manufactured by PBF-LB: A comparison of failure mechanisms between net-shape and electro-chemically milled surface conditions. Eng Failure Anal. 2025;172:109403. doi: 10.1016/j.engfailanal.2025.109403
  39. Bertolini JC. Hydrofluoric acid: A review of toxicity. J Emerg Med. 1992;10(2):163-168. doi: 10.1016/0736-4679(92)90211-B
  40. Kahlin M, Ansell H, Basu D, et al. Improved fatigue strength of additively manufactured Ti6Al4V by surface post processing. Int J Fatigue. 2020;134:105497. doi: 10.1016/j.ijfatigue.2020.105497
  41. Maleki E, Bagherifard S, Bandini M, Guagliano M. Surface post-treatments for metal additive manufacturing: Progress, challenges, and opportunities. Add Manuf 2021;37:101619. doi: 10.1016/j.addma.2020.101619
  42. Grover HJ. Factors by Which Shot Peening Influences the Fatigue Strength of Parts. SAE Technical Paper 540138; 1954. doi: 10.4271/540138
  43. Huang L, Kinnell P, Shipway PH. Removal of heat-formed coating from a titanium alloy using high pressure waterjet: Influence of machining parameters on surface texture and residual stress. J Mater Process Technol. 2015;223:129-138. doi: 10.1016/j.jmatprotec.2015.03.053
  44. Arola DD, McCain ML. Abrasive waterjet peening: A new method of surface preparation for metal orthopedic implants. J Biomed Mater Res. 2000;53(5):536-546. doi: 10.1002/1097-4636(200009)53:5<536:AID-JBM13>3.0.CO;2-V
  45. Arola D, Alade AE, Weber W. Improving fatigue strength of metals using abrasive waterjet peening. Mach Sci Technol. 2006;10(2):197-218. doi: 10.1080/10910340600710105
  46. Yao SL, Wang GY, Yu H, et al. Influence of submerged micro-abrasive waterjet peening on surface integrity and fatigue performance of TA19 titanium alloy. Int J Fatigue. 2022;164:107076. doi: 10.1016/j.ijfatigue.2022.107076
  47. Soyama H. Cavitation peening: A review. Metals (Basel). 2020;10(2):270. doi: 10.3390/met10020270
  48. Soyama H, Korsunsky AM. A critical comparative review of cavitation peening and other surface peening methods. J Mater Process Technol. 2022;305:117586. doi: 10.1016/j.jmatprotec.2022.117586
  49. Soyama H, Kuji C. Improving effects of cavitation peening, using a pulsed laser or a cavitating jet, and shot peening on the fatigue properties of additively manufactured titanium alloy Ti6Al4V. Surf Coat Technol. 2022;451:129047. doi: 10.1016/j.surfcoat.2022.129047
  50. Soyama H, Iga Y. Laser cavitation peening: A review. Appl Sci. 2023;13(11):6702. doi: 10.3390/app13116702
  51. Sato M, Takakuwa O, Nakai M, Niinomi M, Takeo F, Soyama H. Using cavitation peening to improve the fatigue life of titanium alloy Ti-6Al-4V manufactured by electron beam melting. Mater Sci Appl. 2016;7(4):181-191. doi: 10.4236/msa.2016.74018
  52. Petram R, Wisdom C, Montelione A, et al. Removing alpha case from laser powder bed fusion components by cavitation abrasive surface finishing. Materials. 2025;18(9):1977. doi: 10.3390/ma18091977
  53. ASTM International. F2924-14: Standard Specification for Additive Manufacturing Titanium-6 Aluminum-4 Vanadium with Powder Bed Fusion. Vol. 1. United States: ASTM International; 2021.
  54. Standard Terminology for Additive Manufacturing Coordinate Systems and Test Methodologies ASTM Standard: ISO/ASTM 52921-13 (Reapproved 2019), ASTM International, United States.
  55. International Organization for Standardization, ISO 4288:1998. Geometrical Product Specifications (GPS) - Surface Texture: Profile Method - Rules and Procedures for the Assessment of Surface Texture, Geometrical Product Specifications (GPS). Vol. 1998. United Kingdom: International Organization for Standardization; 1998.
  56. Noyan IC, Cohen JB. Residual Stress: Measurement by Diffraction and Interpretation. Berlin: Springer-Verlag; 1987.
  57. He BB. Two-Dimensional x-Ray Diffraction. 2nd ed. United States: John Wiley & Sons, Inc.; 2018. p. 249-325.
  58. ASTM E407-07. Designation: E407- 07 (Reapproved 2015) Standard Practice for Microetching Metals and Alloys. United States: ASTM International; 2015.
  59. Soyama H, Okura Y. The use of various peening methods to improve the fatigue strength of titanium alloy Ti6Al4V manufactured by electron beam melting. AIMS Mater Sci. 2018;5(5):1000-1015. doi: 10.3934/matersci.2018.5.1000
  60. Du Plessis A, Beretta S. Killer notches: The effect of as-built surface roughness on fatigue failure in AlSi10Mg produced by laser powder bed fusion. Add Manuf. 2020;35:101424. doi: 10.1016/j.addma.2020.101424
  61. Vilardell AM, Krakhmalev P, Fredriksson G, et al. Influence of surface topography on fatigue behavior of Ti6Al4V alloy by laser powder bed fusion. In: Procedia CIRP. Vol. 74. Elsevier B.V; 2018. p. 49-52. doi: 10.1016/j.procir.2018.08.028
  62. Barricelli L, Patriarca L, du Plessis A, Beretta S. A comparison of fatigue analysis methods for L-PBF net-shape surfaces in Ti6Al4V parts. Theor Appl Fracture Mech. 2023;128:104143. doi: 10.1016/j.tafmec.2023.104143
  63. Nicoletto G. Influence of rough as-built surfaces on smooth and notched fatigue behavior of L-PBF AlSi10Mg. Add Manuf. 2020;34:101251. doi: 10.1016/j.addma.2020.101251
  64. Simson D, Subbu SK. Effect of process parameters on surface integrity of LPBF Ti6Al4V. Proceedia CIRP. 2022;108: 716-721. doi: 10.1016/j.procir.2022.03.111

 

 

  1. Wang N, Zhu J, Liu B, Zhang X, Zhang J, Tu S. Influence of ultrasonic surface rolling process and shot peening on fretting fatigue performance of Ti-6Al-4V. Chin J Mech Eng. 2021;34(1):1-13. doi: 10.1186/s10033-021-00611-1
  2. Li K, Fu XS, Li RD, et al. Fretting fatigue characteristic of Ti–6Al–4V strengthened by wet peening. Int J Fatigue. 2016;85:65-69. doi: 10.1016/j.ijfatigue.2015.12.013
  3. Mancisidor AM, García-Blanco MB, Quintana I, et al. Effect of post-processing treatment on fatigue performance of Ti6Al4V alloy manufactured by laser powder bed fusion. J Manuf Mater Process. 2023;7(4):119. doi: 10.3390/jmmp7040119
  4. Rigon D, Coppola F, Meneghetti G. Fracture mechanics-based analysis of the fatigue limit of Ti6Al4V alloy specimens manufactured by SLM in as-built surface conditions by means of areal measurements. Eng Fracture Mech. 2024;295:109720. doi: 10.1016/j.engfracmech.2023.109720
  5. Meneghetti G, Rigon D, Gennari C. An analysis of defects influence on axial fatigue strength of maraging steel specimens produced by additive manufacturing. Int J Fatigue. 2019;118:54-64. doi: 10.1016/j.ijfatigue.2018.08.034
  6. Lee S, Rasoolian B, Silva DF, Pegues JW, Shamsaei N. Surface roughness parameter and modeling for fatigue behavior of additive manufactured parts: A non-destructive data-driven approach. Addit Manuf. 2021;46:102094. doi: 10.1016/j.addma.2021.102094

 

 

 

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Materials Science in Additive Manufacturing, Electronic ISSN: 2810-9635 Published by AccScience Publishing