International Journal of Engineering

International Journal of Engineering

Analysis of Microhardness after Turning Process of Ti6Al4V-ELI

Document Type : Original Article

Authors
S. Nipanikar 1
V. Sargade 2
N. Malvade 1
1 Department of Mechanical Engineering, Karmaveer Bhaurao Patil College of Engineering, Satara, Maharashtra, India
2 Department of Mechanical Engineering, Dr. Babasaheb Ambedkar Technological University, Lonere, Dist.: Raigad, Maharashtra, India
10.5829/ije.2026.39.02b.06
Abstract
This study investigated the effect of cutting parameters on the microhardness of Ti6Al4V ELI during dry turning using PVD AlTiN and TiAlN inserts. Addressing the challenge of balancing productivity with stringent surface integrity requirements, this research explored the influence of cutting speed (80, 125, and 170 m/min) and feed rate (0.08, 0.15, and 0.20 mm/rev) on subsurface microhardness. Vickers microhardness testing revealed a clear work hardening tendency, with the highest microhardness observed in the subsurface region. Increasing cutting speed correlated with increased microhardness, particularly when using PVD TiAlN inserts, indicating a greater degree of microstructural alteration. A thicker white layer was observed after turning with PVD AlTiN inserts compared to PVD TiAlN, potentially due to differences in friction coefficient. Maximum microhardness (398 HV0.05) was recorded at 125 m/min cutting speed and 0.20 mm/rev feed rate with PVD TiAlN. The machining affected zone (MAZ) extended to 200 µm and 300 µm below the surface for AlTiN and TiAlN inserts, respectively. These findings provide insights for optimizing machining processes to enhance both surface integrity and productivity in the manufacturing of Ti6Al4V ELI components.

Graphical Abstract

Analysis of Microhardness after Turning Process of Ti6Al4V-ELI
Keywords
Ti6Al4V ELI
PVD AlTiN
PVD TiAlN
Microhardness
Machining Affected Zone

Subjects

  1. Masmiati N, Sarhan AA, Hassan MAN, Hamdi M. Optimization of cutting conditions for minimum residual stress, cutting force and surface roughness in end milling of S50C medium carbon steel. Measurement. 2016;86:253-65. 10.1016/j.measurement.2016.02.049
  2. Davim JP. Surface integrity in machining: Springer; 2010.
  3. Maruda RW, Krolczyk GM, Michalski M, Nieslony P, Wojciechowski S. Structural and microhardness changes after turning of the AISI 1045 steel for minimum quantity cooling lubrication. Journal of Materials Engineering and Performance. 2017;26:431-8. https://doi.org/10.1007/s11665-016-2450-4
  4. Maruda RW, Legutko S, Krolczyk GM, Raos P. Influence of cooling conditions on the machining process under MQCL and MQL conditions. Tehnički vjesnik. 2015;22(4):965-70. https://doi.org/10.17559/tv-20140919143415
  5. Nipanikar S, Sargade V, Guttedar R. Optimization of process parameters through GRA, TOPSIS and RSA models. International Journal of Industrial Engineering Computations. 2018;9(1):137-54. https://doi.org/10.5267/j.ijiec.2017.3.007
  6. Sargade V, Nipanikar S, Meshram S. Analysis of surface roughness and cutting force during turning of Ti6Al4V ELI in dry environment. International Journal of Industrial Engineering Computations. 2016;7(2):257. https://doi.org/10.5267/j.ijiec.2015.10.004
  7. Królczyk G, Nieslony P, Legutko S. Microhardness and surface integrity in turning process of duplex stainless steel (DSS) for different cutting conditions. Journal of Materials Engineering and Performance. 2014;23:859-66. https://doi.org/10.1007/s11665-013-0832-4
  8. Królczyk G, Legutko S, Maruda WR. Influence of Cutting Parameters on Surface Morphology of Austenitic Stainless Steel after Turning. Applied Mechanics and Materials. 2014;657:23-7. https://doi.org/10.4028/www.scientific.net/amm.657.23
  9. Tian WJ, Li Y, Yang ZC, Yao CF, Ren JX. The Influence of Cutting Parameters on Machined Surface Microhardness during High Speed Milling of Titanium Alloy TC17. Advanced Materials Research. 2012;443:127-32. https://doi.org/10.4028/www.scientific.net/amr.443-444.127
  10. Singaravel B, Selvaraj T. A review of micro hardness measurement in turning operation. Applied Mechanics and Materials. 2015;813:274-8. https://doi.org/10.4028/www.scientific.net/amm.813-814.274
  11. Thakur A, Gangopadhyay S, Maity K. Effect of cutting speed and tool coating on machined surface integrity of Ni-based super alloy. Procedia Cirp. 2014;14:541-5. https://doi.org/10.1016/j.procir.2014.03.045
  12. Ibrahim GA, Che Haron CH, Ghani JA. Evaluation of PVD-inserts performance and surface integrity when turning Ti-6Al-4V ELI under dry machining. Advanced Materials Research. 2011;264:1050-5. https://doi.org/10.4028/www.scientific.net/amr.264-265.1050
  13. Ibrahim G, Haron CC, Ghani J. The effect of dry machining on surface integrity of titanium alloy Ti-6Al-4V ELI. Journal of applied sciences. 2009;9(1):121-7. https://doi.org/10.3923/jas.2009.121.127
  14. Ginting A, Nouari M. Surface integrity of dry machined titanium alloys. International Journal of Machine Tools and Manufacture. 2009;49(3-4):325-32. https://doi.org/10.1016/j.ijmachtools.2008.10.011
  15. Che-Haron C. Tool life and surface integrity in turning titanium alloy. Journal of Materials Processing Technology. 2001;118(1-3):231-7. https://doi.org/10.1016/s0924-0136(01)00926-8
  16. Che-Haron C, Jawaid A. The effect of machining on surface integrity of titanium alloy Ti–6% Al–4% V. Journal of materials processing technology. 2005;166(2):188-92. https://doi.org/10.1016/j.jmatprotec.2004.08.012
  17. Rotella G, Dillon O, Umbrello D, Settineri L, Jawahir I. The effects of cooling conditions on surface integrity in machining of Ti6Al4V alloy. The International Journal of Advanced Manufacturing Technology. 2014;71:47-55. https://doi.org/10.1007/s00170-013-5477-9
  18. Hughes J, Sharman A, Ridgway K. The effect of cutting tool material and edge geometry on tool life and workpiece surface integrity. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture. 2006;220(2):93-107. https://doi.org/10.1243/095440506x78192
  19. Ulutan D, Ozel T. Machining induced surface integrity in titanium and nickel alloys: A review. International Journal of Machine Tools and Manufacture. 2011;51(3):250-80. https://doi.org/10.1016/j.ijmachtools.2010.11.003
  20. Ezugwu EO, Bonney J, Da Silva RB, Çakir O. Surface integrity of finished turned Ti–6Al–4V alloy with PCD tools using conventional and high pressure coolant supplies. International Journal of Machine Tools and Manufacture. 2007;47(6):884-91. https://doi.org/10.1016/j.ijmachtools.2006.08.005
  21. Shokrani A, Dhokia V, Newman ST. Investigation of the effects of cryogenic machining on surface integrity in CNC end milling of Ti–6Al–4V titanium alloy. Journal of Manufacturing Processes. 2016;21:172-9. https://doi.org/10.1016/j.jmapro.2015.12.002
  22. Kundrak J, Mamalis A, Gyani K, Bana V. Surface layer microhardness changes with high-speed turning of hardened steels. The International Journal of Advanced Manufacturing Technology. 2011;53:105-12. https://doi.org/10.1007/s00170-010-2840-y
  23. Rahim E, Sasahara H. Investigation of tool wear and surface integrity on MQL machining of Ti-6AL-4V using biodegradable oil. Proceedings of the institution of mechanical engineers, Part B: Journal of Engineering Manufacture. 2011;225(9):1505-11. https://doi.org/10.1177/0954405411402554
  24. Sun J, Guo Y. A comprehensive experimental study on surface integrity by end milling Ti–6Al–4V. Journal of materials processing technology. 2009;209(8):4036-42. https://doi.org/10.1016/j.jmatprotec.2008.09.022
  25. Pawade R, Joshi SS, Brahmankar P. Effect of machining parameters and cutting edge geometry on surface integrity of high-speed turned Inconel 718. International Journal of Machine Tools and Manufacture. 2008;48(1):15-28. https://doi.org/10.1016/j.ijmachtools.2007.08.004
  26. Wang F, Zhao J, Li A, Zhang H. Effects of cutting conditions on microhardness and microstructure in high-speed milling of H13 tool steel. The International Journal of Advanced Manufacturing Technology. 2014;73:137-46. https://doi.org/10.1007/s00170-014-5812-9
  27. Zhang S, Ding T, Li J. Microstructural alteration and microhardness at near-surface of AISI H13 steel by hard milling. Machining Science and Technology. 2012;16(3):473-86. https://doi.org/10.1080/10910344.2012.699387
  28. Zhang T, Shi ZY, Yan B, Qi HJ. Investigation of Size Effect on Micro Hardness of Machined Surface in Micro Cutting. Applied Mechanics and Materials. 2014;602:443-6. https://doi.org/10.4028/www.scientific.net/amm.602-605.443
  29. Wang Q, Liu Z, Wang B, Song Q, Wan Y. Evolutions of grain size and micro-hardness during chip formation and machined surface generation for Ti-6Al-4V in high-speed machining. The International Journal of Advanced Manufacturing Technology. 2016;82:1725-36. https://doi.org/10.1007/s00170-015-7508-1
  30. Nipanikar S, Sonawane G, Sargade V. Tool life of uncoated and coated inserts during turning of Ti6Al4V-ELI under dry and minimum quantity lubrication environments. Int J Eng Trans A. 2023;36:191-8. https://doi.org/10.5829/ije.2023.36.02b.01
  31. Wang F, Zhao J, Li A, Zhao J. Experimental study on cutting forces and surface integrity in high-speed side milling of Ti-6Al-4V titanium alloy. Machining Science and Technology. 2014;18(3):448-63. https://doi.org/10.1080/10910344.2014.926690
International Journal of Engineering
Volume 39, Issue 2
TRANSACTIONS B: Applications
February 2026
Pages 351-360