Elektrik Akım Destekli Sinterleme ile Üretilen Ötektik Yapılı NiAl-34Cr ve NiAl-28Cr-6Mo Alaşımlarının Yüksek Sıcaklık Korozyon Davranışı

Year 2021, Volume: 9 Issue: 1, 79 - 85, 29.01.2021

Cihan Çeper , Nuri Ergin , Özkan Özdemir

https://doi.org/10.21541/apjes.708253

Abstract

Bu çalışmada, NiAl-34Cr ve NiAl-28Cr-6Mo ötektik alaşımları elektrik akım destekli sinterleme (ECAS) yöntemiyle 3500-4200 A akım aralığında 47 dakika bekleme süresiyle üretilmiştir. Elde edilen numunelerin faz incelemeleri, X-ışınları difraksiyon analizi (XRD) yardımıyla gerçekleştirilmiştir. XRD paternlerinden, NiAl-34Cr alaşımının NiAl ve Cr fazları belirlenirken; NiAl-28Cr-6Mo alaşımının ise NiAl ve CrMo fazları ile birlikte düşük miktarda reaksiyona girmemiş Mo fazının varlığı tespit edilmiştir. Archimed prensibine göre yapılan yoğunluk ölçümlerinde NiAl-34Cr ve NiAl-28Cr-6Mo alaşımlarının nispi yoğunlukları sırasıyla %96.2, %97.9 ve mikrosertlik cihazında Vickers sertlik ucu kullanılarak tespit edilen sertlik değerleri sırasıyla 288 ± 18 HV0.5 ve 271 ± 22 HV0.5 olarak belirlenmiştir. Ayrıca numunelerin korozyon özellikleri 25% ağ. K2SO4 + 75% ağ. Na2SO4 tuz ortamında 800, 900 ve 1000°C’de 165 saat (15 Çevrim) sürede sıcak korozyon deneyleriyle incelenmiştir. Korozyon sonrası numunelerin süreye bağlı olarak ağırlık değişimleri, mikroyapı (SEM-EDS) ve faz analizleri gerçekleştirilmiş olup NiAl-34Cr alaşımının korozyon özelliklerinin Mo ilaveli alaşıma kıyasla daha iyi olduğu görülmüştür.

Keywords

İntermetalik, Nikel Alüminid, Ötektik Alaşım, Sıcak Korozyon, Sinterleme

High Temperature Corrosion Behavior of Eutectic Structured NiAl-34Cr and NiAl-28Cr-6Mo Alloys Produced by Electric Current Activated Sintering

Abstract

In this study, NiAl-34Cr and NiAl-28Cr-6Mo eutectic alloys were produced by electric current assisted sintering (ECAS) method in a 3500-4200 A current range with a waiting time of 47 minutes. Phase examinations of the obtained samples were carried out with the help of X-ray diffraction analysis (XRD). While determining NiAl and Cr phases in NiAl-34Cr alloy from XRD patterns; It was determined that NiAl-28Cr-6Mo alloy consists of two phases, together with Mo residues, NiAl and CrMo. According to the Archimed principle, the relative density of NiAl-34Cr and NiAl-28Cr-6Mo alloys was determined as 96.2%, 97.9% respectively. The hardness values of NiAl-34Cr and NiAl-28Cr-6Mo samples were approximately 275 ± 13 HB and 255 ± 20 HB detected. In addition, the corrosion properties of the samples were examined by hot corrosion tests at 800, 900 and 1000°C for 165 hours (15 cycles) in 25% wt. K2SO4 + 75% wt. Na2SO4 salt medium. Weight changes, microstructure (SEM-EDS) and phase analysis of the samples after corrosion were carried out, and the corrosion properties of NiAl-34Cr alloy were found to be better compared to the Mo-added alloy.

Keywords

Intermetallic, Nickel Aluminide, Eutectic Alloy, Hot Corrosion, Sintering

References

• [1] L. Tang, Z. Zhang, S. Li, S. Gong, “Mechanical behaviors of NiAl-Cr(Mo)-based near eutectic alloy with Ti, Hf, Nb and W additions”, Trans. Nonferrous Met. Soc. China Vol. 20, pp. 212-216, 2010.
• [2] K. Hagihara, Y. Sugino, Y. Umakoshi, “The effect of Ti-addition on plastic deformation and fracture behavior of directionally solidified NiAl/Cr(Mo) eutectic alloys”, Intermetallics, Vol. 14, pp. 1326-1331, 2006.
• [3] J. Guo, Z. Wang, L. Sheng, L. Zhou, C. Yuan, Z. Chen, L. Song, “Wear properties of NiAl based materials”, Progress in Natural Science: Materials International Vol. 22, no. 5, pp. 414–425, 2012.
• [4] P.L. Ferrandini, F.L.G.U. Araujo, W.W. Batista, R. Caram, “Growth and characterization of the NiAl–NiAlNb eutectic structure”, Journal of Crystal Growth, Vol. 275, pp. 147–152, 2005.
• [5] A. Güngör, H. Demirtaş, “Microstructure and mechanical properties of Fe-doped NiAl−28Cr−6Mo eutectic alloys”, Trans. Nonferrous Met. Soc. China, Vol. 26, pp. 1025−1031, 2016.
• [6] D.R. Johnson, X.F. Chen, B.F. Oliver, R.D. Noebe, J. D. Whittenberger, “Processing and mechanical properties of in-situ composites from the NiAlCr and the NiAl(Cr,Mo) eutectic systems” Intermetallics, Vol. 3, No 2, pp. 99–113, 1995.
• [7] Y.X. Chen, C.Y. Cui, J.T. Guo, D.X. Li, “Microstructure investigation of NiAl–Cr(Mo) interface in a directionally solidified NiAl–Cr(Mo) eutectic alloyed with refractory metal” Materials Science and Engineering, Vol. A 373, pp. 279–285, 2004.
• [8] D.T. Jiang, J.T. Guo, ”Preliminary investigation of in-situ multi-phase composite NiAl-CrMo/ TiC”, Materials Letters, Vol. 36, pp. 33–37, 1998.
• [9] A. Albiter, M. Salazar, E. Bedolla, R.A.L. Drew, R. Perez, “Improvement of the mechanical properties in a nanocrystalline NiAl intermetallic alloy with Fe, Ga and Mo additions”, Materials Science and Engineering, Vol. A. 347(1–2), pp. 154–164, 2003.
• [10] Y. Liang, J. Guo, Y. Xie, L. Zhou, Z. Hu, “High temperature compressive properties and room temperature fracture toughness of directionally solidified NiAl-based eutectic alloy” Materials and Design, Vol. 30, No. 6, pp. 2181–2185, 2009.
• [11] K. Morsi, “Review; reaction synthesis processing of Ni–Al intermetallic materials”, Vol. 299, pp. 1–15, 2001.
• [12] J.F. Zhang, J. Shen, Z. Shang, L. Wang, H.Z. Fu, “Directional solidification and characterization of NiAl-9Mo eutectic alloy”, Transactions of Nonferrous Metals Society of China (English Edition), Vol. 23, No. 12, pp. 3499–3507, 2013.
• [13] L. Wang, J. Shen, Z. Shang, H. Fu, “Microstructure evolution and enhancement of fracture toughness of NiAl–Cr(Mo)–(Hf,Dy) alloy with a small addition of Fe during heat treatment”, Scripta Materialia, Vol 89, pp. 1–4, 2014.
• [14] L.Y. Sheng , J.T. Guo , H.Q. Ye, “Microstructure and mechanical properties of NiAl–Cr(Mo)/Nb eutectic alloy prepared by injection-casting”, Materials and Design, Vol. 30, pp. 964–969, 2009.
• [15] Garip Yiğit, “Elektrik Akım Destekli Sinterleme Yöntemiyle Üretilen Ti-48Al Esaslı İntermetaliklere Alaşım Elementi İlavesinin Oksidasyon ve Sıcak Korozyon Davranışına Etkisinin İncelenmesi”, Doctoral thesis, Sakarya University of Applied Science, Graduate Education Institute Sakarya, 2019.
• [16] Çeper Cihan, “NiAl-34Cr-X (Fe, Nb, Ti) alaşımının elektrik akım destekli sinterleme (ECAS) yöntemiyle üretimi ve karakterizasyonu”, Master thesis, Sakarya University Institute of Natural Sciences, Sakarya, 2019.
• [17] C. Leyens, B.A. Pint, I.G. Wright, “Effect of composition on the oxidation and hot corrosion resistance of NiAl doped with precious metals”, Surface and Coatings Technology, Vol. 133-134, pp 15-22, 2000.
• [18] M.N. Task, M. Gleeson, F.S. Pettit, G.H. Meier, ”Compositional effects on the Type I hot corrosion of β-NiAl alloys”, Surface & Coatings Technology, Vol. 206, pp. 1552–1557, 2011
• [19] M. Kellner, L. Sprenger, P. Steinmetz, J. Hötzer, B. Nestler, M. Heilmaier, “Phase-field simulation of the microstructure evolution in the eutectic NiAl-34Cr system. Computational Materials Science”, Vol. 128, pp. 379–387, 2017.
• [20] B. Tang, D.A. Cogswell, G. Xu, S. Milenkovic, Y. Cui, “The formation mechanism of eutectic microstructures in NiAl-Cr composites”, Physical Chemistry Chemical Physics, Vol. 18, No 29, pp. 19773–19786, 2016.
• [21]A. Misra, R. Gibala, “Plasticity in multiphase intermetallics”, Intermetallics, Vol. 8, pp. 1025-1034, 2000.
• [22] J.M. Yang, S.M. Jeng, K. Bain, R.A. Amato, “Microstructure and mechanical behaviour of in-situ directional solidified NiAl/Cr(Mo)”, Acta Materialia, Vol. 45, pp. 295-308, 1997.
• [23] Z. Shang, J. Shen, L. Wang, Y. Du, Y. Xiong, H. Fu, “Investigations on the microstructure and room temperature fracture toughness of directionally solidified NiAl-Cr(Mo) eutectic alloy”, Intermetallics, Vol. 57, pp. 25-33, 2015.
• [24] Y.D Liu, J. Sun, Z.L. Pei, W. Li, J.H. Liu, J. Gong, J.Sun, “Oxidation and hot corrosion behavior of NiCrAlYSi+NiAl/cBN abrasive coating”, Corrosion Science, 2020.
• [25] Z. Tang, F. Wang, W. Wu, “Effect of a sputtered TiAlCr coating on hot corrosion resistance of gamma-TiAl”, Intermetallics, Vol. 7, pp. 1271-1274, 1999.