Study on Hardness and Microstructural Properties of Ti-6Al-4V Alloy using Overlapped Multipass Laser Transformation Hardening under Optimized Test Conditions


  • SVERI’S College of Engineering, School of Mechanical Engineering, Solapur, Maharashtra, 413304, India


In this research paper, overlapped multipass Laser Transformation Hardening (LTH) of Ti-6Al-4V titanium alloy sheet of 2 mm thickness was analyzed experimentally for uniformly intense, CW spherical beam moving with constant speed using 2 kW Nd: YAG laser. Experiments were conducted for optimized two sets of laser process parameters: 1. High Laser Process Parameter (HLPP), Lp= 800 Watts, Ss= 3000 mm/min, Fp = -10 mm, with heat input 180 J/cm and 2. Low Laser Process Parameter (LLPP), Lp = 600 Watts, Ss = 2000 mm/min, Fp = -10 mm, with heat input 160 J/cm respectively having same Fp = -10 mm. The maximum, minimum and average hardened depths of 0.27, 0.19 and 0.23 mm respectively, achieved for HLPP were found to be minimum, as compared to the maximum, minimum and average hardened depths of 0.38, 0.29 and 0.33 mm, respectively, for LLPP. Measurements of Vickers micro-hardness survey of the hardened zone of the laser processed Ti-6Al-4V alloy are presented. Vickers micro-hardness of an as-received two-phase (α+β) Ti-6Al-4V titanium alloy is 328 HV. The results showed that Vickers micro-hardness on top of the surface (TS), in hardened or fusion zone (Fz), at the interface of Fz -Haz, in the heat affected zone (Haz) is higher than the bulk material. The high hardness values of 450 HV and 445 HV were investigated on the top surface for high and low laser process parameters respectively. This can be the quality characteristics of the dissolution of small amounts of oxygen, nitrogen, and carbon with hard martensite α’ (transformed β) formation, thereby ensuring an increase in wear resistance of laser treated hardened surface of Ti-6Al-4V considerably in relation to the untreated or base alloy.


Laser Transformation Hardening, Nd:YAG Laser, Overlapped, Scanning Electron Microscopy, Ti-6Al-4V, Vickers Microhardness

Subject Discipline


Full Text:


W. Peng, W. Zeng, Q. Wang and H. Yu, Mater. Des., 51, 95 (2013).

Y. Ning, M. W. Fu, H. Hou, Z. Yao and H. Guo, Mater. Sci. Eng., 528, 1812 (2011). j.msea.2010.11.019

Y. B. Tan, J. L. Duan, L. H. Yang, W. C. Liu, J. W. Zhang and R. P. Liu, J. Mater. Sci. Eng., 609, 226 (2014).

I. Yadroitsev, P. Krakhmalev, and I. Yadroitsava, J. Alloy Comp., 583, 404(2014).

A. Patnaik, N. Poondla, U. BaithiniUdaykar and T. S. Srivastan, Mater. Manuf. Process., 26, 311 (2011).

S. K. Ghosh, and S. Chatterjee, Mater. Manuf. Process., 25, 1317 (2010).

K. Dubeyand V. Yadava, J. Mater. Process Tech., 195, 15 (2008).

C. Yao, B. Xu, J. Huang, P. Zhang and Y. Wu, Optic Laser Eng., 48, 20 (2014).

M. Babic, J. Balic, M. Milfelner, I. Beli, P. Kokol, M. Zorman and P. Panjan, Adv. in Prod. Engg. Mgmt., 8, 25 (2013).

D. S. Badkar, K. S. Pandey and G. Buvanashekaran, Int. J. Adv. Manuf. Tech., 59, 169 (2012). s00170-011-3492-2

H. Ghorbani, M.H.Sohi, M.J. Torkamany, B. Mehrjou, J. Mat. Engg. Perform. 24, 3634 (2015).

Li. Ruifeng, Jin Yajuan, Li. Zhuguo and Qi Kai, J. Mater. Eng. Perform., 23, 3085 (2014).

D. I. Adebiyi, O. Fatoba, S. Pityana and P. Popoola, 30th Int. Confe on Surface Modification Tech. (SMT30)., Milan, Italy (2016).

D. S. Badkar, K. S.Pandey and G. Buvanashekaran, Trans. Nonferr. Met. Soc. of China., 20, 1078 (2010).

J. D. Hahn, Y. C. Shin and M. J. M. Krane, Surf. Eng., 23, 78 (2013).

B. G. Yan and J. C. Liu, Mater. Tech., 27, 5 (2014).

F. Qiu, J. Uusitalo and V. Kujanpää. J. Surf. Engg., 29, 34 (2014).

J. Ciurana, G. Arias and T. Ozel, Mater. Manuf. Process., 24, 358 (2009).

L. J. Yang, S. Jana, S. C. Tarn, L. E. N. Lim, Mater. Manuf. Process., 9, 475 (2007).

C. De. Formanoir, A. Brulard, S. Vivès, G. Martin, F. Prima, S. Michotte, E. Rivière, A. Dolimont and S. Godet. J. Mat. Res.Letters., 5, 201 (2016).

D. S. Badkar. J Mater Metall Eng., 7, 35 (2017).

D. S. Badkar, Journal of Phy., 6, 22 (2017).

D. S. Badkar, K. S. Pandey and G. Buvanashekaran, J. Mats. Met. Engg., 5, 1 (2015).

Laser materials processing lab, WRI, BHEL, 2008-2009.


  • There are currently no refbacks.