Analysis of Cracks in the Pulsed Nd:YAG Laser Welded Joint of Nickel-Based Superalloy

Document Type : Research Paper


1 Department of Materials Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran

2 School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran


The weldability of GTD-111 nickel-based superalloy by pulsed Nd:YAG laser welding with an average power of 250 W was studied, and the microstructural evolution and cracking characteristics were also investigated. The solidification cracking of the fusion zone (FZ) and the intergranular liquation cracking in the heat affected zone (HAZ) were observed in the joint. Solidification cracking was caused by the residual liquid metal originated from the segregation of Ti, Nb and Al elements in the interdendritic region at the last stage of solidification. And the HAZ liquation cracking was associated with the constitutional liquation of 𝛾́, MC carbides, and the melting of Cr-rich boride. Ti was introduced as the most important factor in the formation of the liquation cracks in HAZ by reducing the start temperature of γ−γ́ eutectic reaction and increasing the 𝛾́ dissolution temperature. Chemical analysis of the crack edges at HAZ revealed the presence of high amounts of Ti and Al elements which can be attributed to 𝛾́ partial melting. Gleeble physical simulation revealed that in casting the sample, the liquation started at significantly lower temperatures than in the 1200℃ solution heat treated samples. This is attributed to the boride and intermetallic particles, which had dissolved by the 1200℃ heat treatment. The formation of fine grains due to the high cooling rate of the weld as well as the formation of dispersed carbides in the fusion and heat affected zones led to an increase in the microhardness by about 130 HV compared to the base metal.


[1] M. Berahmand and S. A. Sajjadi, Morphology evolution of γ′precipitates in GTD-111 Ni-based superalloy with heat treatment parameters, International Journal of Materials Research 104 (2013) 275-280.
[2] C.Yang, Y. Xu, Z. Zhang, H. Nie, X. Xiao, G. Jia, Improvement of stress rupture, life of GTD-111 by second solution heat treatment, Materials & Design 45 (2013) 308-315.
[3] M. Taheri, A. Salemi-Golezani, K. Shirvani, Effect of Aluminide coating on rapture behavior of Ni-based superalloy GTD-111 in high temperature, Advanced Material Research 457 (2012) 330-333.
[4] Gh. R. Razavi, J. Razavi, M. Taheri, M. Saboktakin, M 2013 Investigation mechanical properties and microstructure of pulsed Nd:YAG laser welding titanium, International Journal of Materials and Mechanics Engineering 2 No. 3 (2013).
[5] L. O. Osoba, R. K. Sidhu, O. A. Ojo, On preventing HAZ cracking in laser welded DS Rene 80 superalloy, Materials Science and Technology 27 (2011) 897-902.
[6] W. Wang, Li. Jiang, Li. Chaowen, Effects of post-weld heat treatment on microstructure and mechanical properties of Hastelloy N superalloy welds, Materials Today Communications 19 (2019) 230-237.
[7] R. A. Buckson, O. A. Ojo, Analysis of the influence of laser welding on fatigue crack growth behavior in a newly developed nickel-base superalloy, Journal of Materials Engineering and Performance 24 (2015) 353–361.
[8] M. Taheri, A. Halvaee, F. Kashani-Bozorg, Effect of Pre- and Post-weld Heat Treatment on Microstructure and Mechanical Properties of GTD-111 Superalloy Welds, Metals and Materials International 28 (2019).
[9] M. Montazeri, F. Malek-Ghaini, The liquation cracking behavior of IN738LC superalloy during low power Nd:YAG pulsed laser welding, Material Characterization 67 (2012) 65-73.
[10] M. Pang C. Y. Zheng, Microstructure study of laser welding cast nickel-based superalloy K418, Journal of Materials Processing Technology 207 (2008) 271-275.
[11] A. T. Egbewande, H. R. Zhang, R.K. Sidhu, O. A. Ojo, Improvement in laser weldability of INCONEL 738 superalloy through microstructural modification, Metallurgical and Materials Transactions A 40 (2009) 2694-2704.
[12] L. O. Osoba, R. G. Ding, O. A. Ojo, Microstructural analysis of laser weld fusion zone in Haynes 282 superalloy, Materials Characterization 65 (2012) 93-99.
[13] O. A. Ojo, N. L. Richards, M. C. Chaturvedi, Contribution of constitutional liquation of gamma prime precipitate to weld HAZ cracking of cast Inconel 738 superalloy, Scripta Materialia 50 (2004) 641-646.
[14] M. F. Chiang, C. Chen, Induction-assisted laser welding of IN-738 nickel–base superalloy, Materials Chemistry and Physics 114 (2009) 415-419.
[15] M. A. Rezaei, H. Naffakh-Moosavy, The effect of pre-cold treatment on microstructure weldability and mechanical properties in laser welding of superalloys, Journal of Manufacturing Processes 34 (2018) 339-348.
[16] M. Montazeri, F. Mmalek, O. A. Ojo, Heat Input and the Liquation Cracking of Laser Welded IN738LC Superalloy, Welding Journal 92 (2013) 258-264.
[17] M. R. Jelokhani-Niaraki, N. B. Mostafa Arab, H Naffakh-Moosavy, M Ghoreishi, The systematic parameter optimization in the Nd:YAG laser beam welding of IN 625, International Journal of Advanced Manufacturing Technology 84 (2016) 2537-2546.
[18] M. J. Torkamany, S. Tahamtan, J. Sabbaghzadeh, Dissimilar welding of carbon steel to 5754 aluminum alloy by Nd:YAG pulsed laser, Materials & Design 31 (2010) 458-465.
[19] M. Junaid, F. Nawaz Khan, K. Rahman, M. Nadeem Baig, Effect of laser welding process on the microstructure, mechanical properties and residual stresses in Ti-5Al-2.5Sn alloy, Optics and Laser Technology 97(2017) 405-419.
[20] B. K. Lee, W. Y. Song, D. U. Kim, Effect of Bonding Temperatures on the Transient Liquid Phase Bonding of a Directionally Solidified Ni-based Superalloy, GTD-111, Metals and Materials International 13 (2007) 59-65.
[21] M. Taheri, A. Halvaee, S. F. Kashani-Bozorg 2019 Effect of Nd: YAG pulsed-laser welding parameters on microstructure and mechanical properties of GTD-111 superalloy joint, Materials Research Express 6 (2019).
[22] Sindo Kou, Welding metallurgy, John wiley publication, second edition, 2003.
[23] G. Asala, O. A. Ojo, On post-weld heat treatment cracking in TIG welded superalloy ATI 718Plus, Results in Physics 6 (2016) 196-198.
[24] K. Han, H. Wang, L. Shen, B. Zhang, Analysis of cracks in the electron beam welded joint of K465 nickel-base superalloy, Vacuum 157 (2018) 21-30.
[25] F. Caiazzo, V. Alfieri, F. Cardaropoli, V. Sergi, Investigation on edge joints of Inconel 625 sheets processed with laser welding, Optics and Laser Technology 93 (2017) 180-186.
[26] T. E. Bower, H. D. Brody, M. C. Flemings, Measurement of solute redistribution in dendritic solidification, AIME MET SOC TRANS 236 (1996) 615-624.
[27] K. Simant-Bal, J. D. Majumdar, A. R. Choudhury, Effect of post-weld heat treatment on the tensile strength of laser beam welded Hastelloy C-276 sheets at different heat inputs, Journal of Manufacturing Processes, 37 (2019) 578-594.
[28] E. Scheil, Remarks on the crystal layer formation, Zeitschrift für Metallkunde 34 (1942) 70-72.
[29] J. N. Dupont, Microstructural development and solidification cracking susceptibility of a stabilized stainless steel, Welding Journal 52 (1999) 253-263.
[30] H. Moosavy, M. R. Aboutalebi, S. H. Seyedein, An analytical algorithm to predict weldability of precipitation-strengthened nickel-base superalloys, Journal of Materials Processing Technology 212 (2012) 2210-2218.
[31] O. A. Ojo, N. L. Richards, M. C. Chaturvedi, Liquid film migration of constitutionally liquated γ′ in weld HAZ of IN738LC superalloy, Scripta Materialia 51 (2004) 141-146.
[32] A. Dadkhah, A. Kermanpur, On the precipitation hardening of the directionally solidified GTD-111 Ni-base superalloy: Microstructures and mechanical properties, Materials Science and Engineering: A 658 (2017) 79-86.
[33] J. J. Pepe, W. F. Salvage, Weld. J 46 (1967) 411s-26s.
[34] C. Yang, Y. Xu, Z. Zhang, H. Nie, Z. Shen, Improvement of stress-rupture life of GTD-111 by second solution heat treatment, Materials & Design 45 (2013) 308-31.
[35] M. Paidar, A. Khodabandeh, M. Lali Sarab, M. Taheri, Effect of welding parameters (plunge depths of shoulder, pin geometry, and tool rotational speed) on the failure mode and stir zone characteristics of friction stir spot welded aluminum 2024-T3 sheets, Journal of Mechanical Science and Technology 29 (2015) 4639-4644.