A Survey on Post-Weld Modification of Microstructural and Mechanical Properties of GTAWed Aluminum Butt Joints Through FSP and T6 Heat Treatment
Fusion welding is a commonly applied manufacturing process in all fields of industry. Some imperfections (formation of coarse-grained microstructure, decrease in mechanical property, etc.) can occur especially in the fusion welding-based fabrication of aluminum alloys which have specific features, such as having high thermal conductivity, expansion coefficient, high hydrogen solubility in the liquid state, and oxide layer on the surface. Therefore, the enhancement of microstructure and mechanical properties in terms of the lifespan and strength of the fusion-welded joints is crucial for most applications. In the study, the effects of friction stir processing (FSP) and T6 heat treatment, applied as post-weld processing, on the weld zone properties of the gas tungsten arc welded (GTAWed) AA6082 plates were investigated. The effects of the post-weld processings (FSP and T6 heat treatment) on mechanical and microstructural features were analyzed via microstructural examination and microhardness measurements and tensile strength testing. It was observed that the dendritic microstructure in the processed region (stir zone) of the weld bead was destroyed and fine-grained microstructure was formed via FSP. Additionally, the findings showed that heat input occurred during FSP led to broaden of heat affected zone (HAZ) and decrease the hardness in a wider region. It was also determined that the mechanical characteristics of the GTAWed joint were increased but in contrast, the toughness was decreased through T6 post-weld heat treatment.
Tig Alın Kaynaklı Alüminyum Birleştirmelerin Mikroyapı ve Mekanik Özelliklerinin SKP ve T6 Isıl İşlemi Yoluyla Kaynak Sonrası Modifikasyonu Üzerine Bir Araştırma
Ergitme kaynağı ile birleştirme endüstrinin her alanında yaygın olarak uygulanan imalat yöntemlerindendir. Özellikle yüksek ısıl iletim ve genleşme katsayısına sahip, sıvı halde hidrojen çözünürlüğü yüksek olan ve yüzeyinde rijit oksit tabakası bulunan alüminyum alaşımlarının ergitme kaynağıyla imalatında iri tane oluşumu, mekanik özelliklerde düşüş vb. olumsuzluklar gerçekleşebilmektedir. Bu nedenle ergitme kaynaklı birleştirmelerin ömürleri ve mukavemetleri açısından kaynak sonrası işlem ile kaynak bölgesinin iç yapı ve mekanik özelliklerinin iyileştirilmesi çoğu uygulama için önemli rol oynamaktadır. Çalışmamızda, tungsten inert gaz (TIG) kaynağı ile birleştirilen AA6082-T6 plakaların kaynak bölgesi özelliklerine kaynak sonrası işlem olarak uygulanan sürtünme karıştırma prosesi (SKP) ve T6 ısıl işleminin etkileri araştırılmıştır. SKP ve T6 ısıl işleminin mekanik özelliklere ve iç yapıya etkileri çekme testi, mikrosertlik testi ve mikroyapı incelemeleri ile araştırılmıştır. SKP ile kaynak dolgusunun işlem gören bölgesindeki (karıştırma bölgesi) dendritik tanelerin parçalanarak ince taneli iç yapının elde edildiği tespit edilmiştir. Bununla birlikte, SKP’nin malzemede oluşturduğu ısıl girdi ile ısıdan etkilenen bölgenin (IEB) genişlemesine ve sertliğin daha geniş bölgede düşmesine sebep olduğu gözlemlenmiştir. Kaynak sonrası uygulanan T6 ısıl işlemi ile kaynaklı birleştirmenin mekanik özelliklerin arttırıldığı ancak tokluğunun azaldığı gözlemlenmiştir.
___
- Aliakbari, S., Ketabchi, M., Mirsalehi, S. E. 2018. “Through-thickness friction stir processing; a low-cost technique for fusion welds repair and modification in AA6061 alloy,” Journal of Manufacturing Processes, vol. 35, p. 226–232. https://doi.org/10.1016/j.jmapro.2018.08.006
- Prasad,V. V., Lingaraju, D. 2017. “Effect of different edge preparations on the tensile and hardness properties of GTAW welded 6082 aluminum alloy,” Materials Today: Proceedings, vol. 4, no. 2 (A), p. 157-165. https://doi.org/10.1016/j.matpr.2017.01.009
- Costa, J. D. M., Jesus, J. S., Loureiro, A., Ferreira, J. A. M., Borrego, L. P. 2014. “Fatigue life improvement of mig welded aluminium T-joints by friction stir processing,” International Journal of Fatigue, vol. 61, p. 244-254. https://doi.org/10.1016/j.ijfatigue.2013.11.004
- Walter, V., Weidenmann, K. A., Schulze, V. 2014. “A comparison of FSW, BHLW and TIG joints for Al-Si-Mg alloy (EN AW-6082 T6),” Procedia CIRP, vol. 18, p. 120-125. https://doi.org/10.1016/j.procir.2014.06.118
- Roeen, G. A., Yousefi, S. G., Emadi, R., Shooshtari, M., Lotfian., S. 2021. "Remanufacturing the AA5052 GTAW welds using friction stir processing," Metals, vol. 11, no. 5: 749. https://doi.org/10.3390/met11050749
- Mehdi, H., Mishra, R. S. 2020. “Investigation of mechanical properties and heat transfer of welded joint of AA6061 and AA7075 using TIG+FSP welding approach,” Journal of Advanced Joining Processes, vol. 1,100003. https://doi.org/10.1016/j.jajp.2020.100003
- Gómez de Salazar, J. M., Ureña, A., Villauriz, E., Manzanedo, S., Barrena, I. 1999. “TIG and MIG welding of 6061 and 7020 aluminium alloys. Microstructural studies and mechanical properties,” Welding International, vol. 13, no. 4, p. 293-295. https://doi.org/10.1080/09507119909447381
- Rodríguez-Hernández, T., Cruz-Hernández, V. L., García-Rentería, M. A., Torres-Gonzalez, R., García-Villarreal, S., Curiel-López, F. F., Falcón-Franco, L. A. 2020. “First assessment on the microstructure and mechanical properties of GTAW-GMAW hybrid welding of 6061-T6 AA,” Journal of Manufacturing Processes, vol. 59, p. 658-667. https://doi.org/10.1016/j.jmapro.2020.09.069
- Williams, J. C., Starke, E. A. 2003. “Progress in structural materials for aerospace systems1,” Acta Materialia, vol. 51, no. 19, p. 5775-5799. https://doi.org/10.1016/j.actamat.2003.08.023
- Karagöz, T. 2021. “TIG kaynağı yapılan alüminyum bir sac parçanın çarpılma miktarının incelenmesi,” Mühendis ve Makina, cilt 62, sayı 702, s. 55-69. https://dergipark.org.tr/tr/pub/muhendismakina/issue/60660/894618
- Savaş, A. 2021. “TIG kaynağı ile gerçekleştirilen sert dolgu sırasında oluşan artık gerilme ve deformasyonların modellenmesi,” Mühendis ve Makina, cilt 62, sayı 704, s. 620-636. https://doi.org/10.46399/muhendismakina.937623
- Serindağ, H. T., Tardu, C., Kırçiçek, İ. Ö., Çam, G. 2021. “Gaz tungsten ark kaynaklı 9Ni kriyojenik çelik bağlantının içyapı ve mekanik özelliklerinin belirlenmesi,” Mühendis ve Makina, cilt 63, sayı 706, s. 117-137. https://dergipark.org.tr/tr/pub/muhendismakina/issue/68844/1085742
- Zhang, Yq., Zhang, Hq., Li, Jf., Liu, Wm. 2009. “Effect of heat input on microstructure and toughness of coarse grain heat affected zone in Nb microalloyed HSLA steels,” Journal of Iron and Steel Research International, vol. 16, p. 73–80. https://doi.org/10.1016/S1006-706X(10)60014-3
- Türker, M. 2017. “The effect of welding parameters on microstructural and mechanical properties of HSLA S960QL type steel with submerged arc welding,” Süleyman Demirel University Journal of Natural and Applied Sciences, vol. 21, no. 3, p. 673-682. https://doi.org/10.19113/sdufbed.38730
- Nathan, S. R., Balasubramanian, V., Malarvizhi, S., Rao, A. G. 2015. “Effect of welding processes on mechanical and microstructural characteristics of high strength low alloy naval grade steel joints,” Defence Technology, vol. 11, no. 3, p. 308-317. https://doi.org/10.1016/j.dt.2015.06.001
- Köse, C., Topal, C. 2019. “Effect of post weld heat treatment and heat input on the microstructure and mechanical properties of plasma arc welded AISI 410S ferritic stainless steel,” Materials Research Express, vol. 6, no. 6. https://doi.org/10.1088/2053-1591/ab09b6
- Liang, Y., Shen, J., Hu, S., Wang, H., Pang, J. 2018 “Effect of TIG current on microstructural and mechanical properties of 6061-T6 aluminium alloy joints by TIG–CMT hybrid welding,” Journal of Materials Processing Technology, vol. 255, p. 161-174. https://doi.org/10.1016/j.jmatprotec.2017.12.006
- Mehdi, H., Mishra, R.S. 2019. “Study of the influence of friction stir processing on tungsten inert gas welding of different aluminum alloy,” SN Applied Sciences, vol. 1, no.7. https://doi.org/10.1007/s42452-019-0712-0
- Roy, S., Fisher, J. W., Yen, B. T. 2003, “Fatigue resistance of welded details enhanced by ultrasonic impact treatment (UIT),” International Journal of Fatigue, vol. 25, no. 9–11, p. 1239-1247. https://doi.org/10.1016/S0142-1123(03)00151-8
- Liu, C., Chen, D., Hill, M. R., Tran, M.N., Zou, J. 2017. “Effects of ultrasonic impact treatment on weld microstructure, hardness, and residual stress,” Materials Science and Technology, vol. 33, no.14, p. 1601-1609. https://doi.org/10.1080/02670836.2017.1299277
- Abbasi, M., Givi, M., Bagheri., B. 2020. “New Method to Enhance the Mechanical Characteristics of Al-5052 Alloy Weldment Produced by Tungsten Inert Gas,” Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture. https://doi.org/10.1177/0954405420929777
- Gangil, N., Maheshwari, S., Siddiquee, A. N., Abidi, M.H., El-Meligy, M.A., Mohammed, J.A. 2019. “Investigation on friction stir welding of hybrid composites fabricated on Al–Zn–Mg–Cu alloy through friction stir processing,” Journal of Materials Research and Technology, vol. 8, no. 5, p. 3733-3740. https://doi.org/10.1016/j.jmrt.2019.06.033
- Badkoobeh, F., Mostaan, H., Rafiei, M., Bakhsheshi-Rad, H. R., Berto. F. 2021. "Friction Stir Welding/Processing of Mg-Based Alloys: A Critical Review on Advancements and Challenges," Materials, vol. 14, no. 21, 6726. https://doi.org/10.3390/ma14216726
- Ma, Z. Y., Mishra, R. S., Mahoney, M. W. 2002. “Superplastic deformation behaviour of friction stir processed 7075Al alloy,” Acta Materialia, vol. 50, no. 17, p. 4419-4430. https://doi.org/10.1016/S1359-6454(02)00278-1
- He, X., Gu, F., Ball, A. 2014. “A review of numerical analysis of friction stir welding,” Progress in Materials Science, vol. 65, p. 1-66. https://doi.org/10.1016/j.pmatsci.2014.03.003
- Jesus, J. S., Costa, J. M., Loureiro, A., Ferreira, J. M. ”Fatigue strength improvement of GMAW T-welds in AA 5083 by friction-stir processing,” International Journal of Fatigue, vol. 97, p. 124-134. https://doi.org/10.1016/j.ijfatigue.2016.12.034
- da Silva, J., Costa, J. M., Loureiro, A., Ferreira, J. M. 2013. “Fatigue behaviour of AA6082-T6 MIG welded butt joints improved by friction stir processing,” Materials & Design, vol. 51, p. 315-322. https://doi.org/10.1016/j.matdes.2013.04.026
- Borrego, L. P., Costa, J. D., Jesus, J. S., Loureiro, A. R., Ferreira, J. M., “Fatigue life improvement by friction stir processing of 5083 aluminium alloy MIG butt welds,” Theoretical and Applied Fracture Mechanics, vol. 70, p. 68-74, https://doi.org/10.1016/j.tafmec.2014.02.002
- Gandra, J., Miranda, R. M., Vilaça, P., “Effect of overlapping direction in multipass friction stir processing,” Materials Science and Engineering: A, vol. 528, no. 16–17, p. 5592-5599. https://doi.org/10.1016/j.msea.2011.03.105
- Cerit, M., Kokumer, O., Genel, K. 2010. “Stress concentration effects of undercut defect and reinforcement metal in butt welded joint,” Engineering Failure Analysis, vol. 17, no. 2, p. 571-578. https://doi.org/10.1016/j.engfailanal.2009.10.010
- Mabuwa, S., Msomi, V., 2021. “The effect of FSP conditions towards microstructure and mechanical properties of the AA6082/AA8011 TIG-welded joint,” Materials Research Express, vol. 8, 066514. https://doi.org/10.1088/2053-1591/ac0735
- Sameer, MD, Birru, A. K. 2019. “Mechanical and metallurgical properties of friction stir welded dissimilar joints of AZ91 magnesium alloy and AA 6082-T6 aluminium alloy,” Journal of Magnesium and Alloys, vol. 7, no. 2, p. 264-271. https://doi.org/10.1016/j.jma.2018.09.004
- Starink, M. J., Deschamps, A., Wang, S. C. “The strength of friction stir welded and friction stir processed aluminium alloys,” Scripta Materialia, vol. 58, no. 5, p. 377-382. https://doi.org/10.1016/j.scriptamat.2007.09.061
- Lakshminarayanan, A.K., Balasubramanian, V., Elangovan, K. 2009. “Effect of welding processes on tensile properties of AA6061 aluminium alloy joints”, The International Journal of Advanced Manufacturing Technology, vol. 40, p. 286–296. https://doi.org/10.1007/s00170-007-1325-0