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Heavy Deformation and High-Temperature Annealing Microstructure and Texture Studies of TaHfNbZrTi Equiatomic Refractory High Entropy Alloy

Authors: Veeresham Mokali


The refractory alloys are crucial for high-temperature applications to improve performance and reduce cost. They are used in several applications such as aerospace, outer space, military and defense, nuclear powerplants, automobiles, and industry. The conventional refractory alloys show greater stability at high temperatures and in contrast they have operational limitations due to their low melting temperatures. However, there is a huge requirement to improve the refractory alloys’ operational temperatures and replace the conventional alloys. The newly emerging refractory high entropy alloys (RHEAs) could be alternative materials for conventional refractory alloys and fulfill the demands and requirements of various practical applications in the future. The RHEA TaHfNbZrTi was prepared through an arc melting process. The annealing behavior of severely deformed equiatomic RHEATaHfNbZrTi has been investigated. To obtain deformed condition, the alloy is cold-rolled to 90% thickness reduction and then subjected to an annealing process to observe recrystallization and microstructural evolution in the range of 800 °C to 1400 °C temperatures. The cold-rolled – 90% condition shows the presence of microstructural heterogeneity. The annealing microstructure of 800 °C temperature reveals that partial recrystallization and further annealing treatment carried out annealing treatment in the range of 850 °C to 1400 °C temperatures exhibits completely recrystallized microstructures, followed by coarsening with a degree of annealing temperature. The deformed and annealed conditions featured the development of body-centered cubic (BCC) fiber textures. The experimental investigation of heavy deformation and followed by high-temperature annealing up to 1400 °C temperature will contribute to the understanding of microstructure and texture evolution of emerging RHEAs.

Keywords: Refractory high entropy alloys, cold-rolling, annealing, microstructure, texture.

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[1] Yeh, J. W., Chen, S. K., Lin, S. J., Gan, J. Y., Chin, T. S., Shun, T. T., ... & Chang, S. Y. (2004). Nanostructured high‐entropy alloys with multiple principal elements: novel alloy design concepts and outcomes. Advanced Engineering Materials, 6(5), 299-303.
[2] Yeh, J.W., Alloy Design Strategies and Future Trends in High-Entropy Alloys. Jom, 2013.65(12): p. 1759-1771.
[3] Otto, F., Yang, Y., Bei, H., & George, E. P. (2013). Relative effects of enthalpy and entropy on the phase stability of equiatomic high-entropy alloys. Acta Materialia, 61(7), 2628- 2638.
[4] Yao, M. J., Pradeep, K. G., Tasan, C. C., & Raabe, D. (2014). A novel, single phase, non- equiatomic FeMnNiCoCr high-entropy alloy with exceptional phase stability and tensile ductility. Scripta Materialia, 72, 5-8.
[5] Zhang, Y., Zuo, T. T., Tang, Z., Gao, M. C., Dahmen, K. A., Liaw, P. K., & Lu, Z. P. (2014). Microstructures and properties of high-entropy alloys. Progress in Materials Science, 61, 1-93.
[6] Lu, Z. P., Wang, H., Chen, M. W., Baker, I., Yeh, J. W., Liu, C. T., & Nieh, T. G. (2015). An assessment on the future development of high-entropy alloys: summary from a recent workshop. Intermetallics, 66, 67-76.
[7] Tsai, M.-H. and J.-W. Yeh, High-Entropy Alloys: A Critical Review. Materials Research Letters, 2014. 2(3): p. 107-123.
[8] Gao, M.C., Progress in High-Entropy Alloys. Jom, 2014. 66(10): p. 1964-1965.
[9] Zhang, Z., Mao, M. M., Wang, J., Gludovatz, B., Zhang, Z., Mao, S. X., ... & Ritchie, R. O. (2015). Nanoscale origins of the damage tolerance of the high-entropy alloy CrMnFeCoNi. Nature communications, 6, 10143.
[10] Gludovatz, B., Hohenwarter, A., Catoor, D., Chang, E. H., George, E. P., & Ritchie, R. O. (2014). A fracture-resistant high-entropy alloy for cryogenic applications. Science, 345(6201), 1153-1158.
[11] Pickering, E.J. and N.G. Jones, High-entropy alloys: a critical assessment of their founding principles and future prospects. International Materials Reviews, 2016. 61(3): p. 183-202.
[12] Z., Pradeep, K. G., Deng, Y., Raabe, D., & Tasan, C. C. (2016). Metastable high- entropy dual-phase alloys overcome the strength–ductility trade-off. Nature, 534(7606), 227.
[13] Senkov, O. N., Wilks, G. B., Miracle, D. B., Chuang, C. P., & Liaw, P. K. (2010). Refractory high-entropy alloys. Intermetallics, 18(9), 1758-1765.
[14] Senkov, O.N., C. Woodward, and D.B. Miracle, Microstructure and Properties of Aluminum-Containing Refractory High-Entropy Alloys. Jom, 2014. 66(10): p. 2030-2042.
[15] Senkov, O.N., et al., Mechanical properties of low-density, refractory multi-principal element alloys of the Cr-Nb-Ti-V-Zr system. Materials Science and Engineering a- Structural Materials Properties Microstructure and Processing, 2013. 565: p. 51-62.
[16] Senkov, O. N., Senkova, S. V., Woodward, C., & Miracle, D. B. (2013). Low-density, refractory multi-principal element alloys of the Cr–Nb–Ti–V–Zr system: Microstructure and phase analysis. Acta Materialia, 61(5), 1545-1557.
[17] Gao, M. C., Carney, C. S., Doğan, Ö. N., Jablonksi, P. D., Hawk, J. A., & Alman, D. E. (2015). Design of refractory high-entropy alloys. Jom, 67(11), 2653-2669.
[18] Huang, H., Wu, Y., He, J., Wang, H., Liu, X., An, K., ... & Lu, Z. (2017). Phase‐transformation ductilization of brittle high‐entropy alloys via metastability engineering. Advanced Materials, 29(30), 1701678.
[19] Zou, Y., Maiti, S., Steurer, W., & Spolenak, R. (2014). Size-dependent plasticity in an Nb25Mo25Ta25W25 refractory high-entropy alloy. Acta Materialia, 65, 85-97.
[20] Sheikh, S., Shafeie, S., Hu, Q., Ahlström, J., Persson, C., Veselý, J., ... & Guo, S. (2016). Alloy design for intrinsically ductile refractory high-entropy alloys. Journal of Applied Physics, 120(16), 164902.
[21] Senkov, O. N., Scott, J. M., Senkova, S. V., Meisenkothen, F., Miracle, D. B., & Woodward, C. F. (2012). Microstructure and elevated temperature properties of a refractory TaNbHfZrTi alloy. Journal of Materials Science, 47(9), 4062-4074.
[22] Senkov, O. N., Wilks, G. B., Scott, J. M., & Miracle, D. B. (2011). Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys. Intermetallics, 19(5), 698-706.
[23] Senkov, O.N. and C.F. Woodward, Microstructure and properties of a refractory NbCrMo0.5Ta0.5TiZr alloy. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing, 2011. 529: p. 311-320.
[24] Dimiduk, D. M., Woodward, C., Miracle, D. B., Senkov, O. N., & Senkova, S. V. (2012), Oxidation behavior of a refractory NbCrMo0.5Ta0.5TiZr alloy. Journal of Materials Science, 2012. 47(18): p. 6522-6534.
[25] Gorr, B., Azim, M., Christ, H. J., Mueller, T., Schliephake, D., & Heilmaier, M. (2015). Phase equilibria, microstructure, and high temperature oxidation resistance of novel refractory high-entropy alloys. Journal of Alloys and Compounds, 624, 270-278.
[26] Juan, C. C., Tsai, M. H., Tsai, C. W., Lin, C. M., Wang, W. R., Yang, C. C., ... & Yeh, J. W. (2015). Enhanced mechanical properties of HfMoTaTiZr and HfMoNbTaTiZr refractory high-entropy alloys. Intermetallics, 62, 76-83.
[27] Wu, Y. D., Cai, Y. H., Wang, T., Si, J. J., Zhu, J., Wang, Y. D., & Hui, X. D. (2014). A refractory Hf25Nb25Ti25Zr25 high-entropy alloy with excellent structural stability and tensile properties. Materials Letters, 130, 277-280.
[28] Senkov, O. N., Scott, J. M., Senkova, S. V., Miracle, D. B., & Woodward, C. F. (2011). Microstructure and room temperature properties of a high-entropy TaNbHfZrTi alloy. Journal of alloys and compounds, 509(20), 6043-6048.
[29] Eleti, R. R., Raju, V., Veerasham, M., Reddy, S. R., & Bhattacharjee, P. P. (2018). Influence of strain on the formation of cold-rolling and grain growth textures of an equiatomic HfZrTiTaNb refractory high entropy alloy. Materials Characterization, 136, 286-292.
[30] Hansen, N. and D.J. Jensen, Development of microstructure in FCC metals during cold work. Philosophical Transactions of the Royal Society of London Series a-Mathematical Physical and Engineering Sciences, 1999. 357(1756): p. 1447-1469.
[31] Pa, M., DP, D., Chandra, T., & CR, K. (1996). Grain growth predictions in microalloyed steels. ISIJ international, 36(2), 194-200.
[32] Humphreys, F.J. and M. Hatherly, in Recrystallization and Related Annealing Phenomena (Second Edition). 2004, Elsevier: Oxford.
[33] Verlinden, B., Driver, J., Samajdar, I., & Doherty, R. D. (2007). Thermo-mechanical processing of metallic materials (Vol. 11). Elsevier.