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Crystallographic and Compositional Evolution of Ordered B2 and Disordered BCC Phases During Isothermal Annealing of Refractory High-Entropy Alloys

Published online by Cambridge University Press:  10 June 2022

Sriswaroop Dasari ,
Abhishek Sharma ,
Vishal Soni ,
Zachary Kloenne ,
Hamish Fraser  and
Rajarshi Banerjee Open the ORCID record for Rajarshi Banerjee [Opens in a new window]
Sriswaroop Dasari*
Affiliation:
Department of Materials Science & Engineering, University of North Texas, Denton, TX 76207, USA
Abhishek Sharma
Affiliation:
Department of Materials Science & Engineering, University of North Texas, Denton, TX 76207, USA
Vishal Soni
Affiliation:
Department of Materials Science & Engineering, University of North Texas, Denton, TX 76207, USA
Zachary Kloenne
Affiliation:
Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
Hamish Fraser
Affiliation:
Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
Rajarshi Banerjee*
Affiliation:
Department of Materials Science & Engineering, University of North Texas, Denton, TX 76207, USA
*
*Corresponding authors: Sriswaroop Dasari, E-mail: [email protected]; Rajarshi Banerjee, E-mail: [email protected]
*Corresponding authors: Sriswaroop Dasari, E-mail: [email protected]; Rajarshi Banerjee, E-mail: [email protected]
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Abstract

Refractory high-entropy alloys (RHEAs) are promising candidates for next-generation high-temperature materials. RHEAs containing Al, often exhibit a checkered pattern microstructure comprising a combination of disordered BCC and ordered B2 phases. Since the ordered B2 phase is based on the BCC parent matrix, distinguishing these two phases can be rather challenging. Advanced characterization techniques are necessary for a reliable qualitative and quantitative analysis of BCC and B2 phases in RHEAs. Additionally, there is a tendency for transformation of the ordered B2 phase into more complex ordered-omega type phases that are usually deleterious to mechanical properties. The current study focuses on the phase stability of a candidate RHEA, Al0.5Mo0.5NbTa0.5TiZr. Correlative transmission electron microscopy (TEM) and atom probe tomography (APT) have been employed to investigate the phase stability and transformation pathway of this RHEA when isothermally annealed at 800°C. The results show that a metastable two-phase BCC + B2 microstructure formed at the early stages of decomposition, eventually transforming into a three-phase BCC + B2 + hP18 microstructure. The hP18 phase is an ordered omega derivative of the ordered B2 phase. The correlative microscopy techniques (TEM and APT) reveal a very interesting interplay of compositional partitioning between the different phases and their respective stability.

Keywords

B2 precipitationcorrelative microscopyordered omega phaseorderingrefractory high-entropy alloys
Type
Original Article
Information
Microscopy and Microanalysis , First View , pp. 1 - 11
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Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of the Microscopy Society of America

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References

Banerjee, S & Mukhopadhyay, P (2007). Phase Transformations - Examples from Titanium and Zirconium Alloys. Oxford, UK: Pergamon.Google Scholar
Banerjee, S, Tewari, R & Dey, GK (2006). Omega phase transformation – Morphologies and mechanisms. Int J Mater Res 97, 963–977.Google Scholar
Cahn, JW (1962). On spinodal decomposition in cubic crystals. Acta Metall 10, 179–183.CrossRefGoogle Scholar
Dasari, S, Soni, V, Sharma, A, Senkov, ON, Miracle, DB, Fraser, HL, Wang, Y & Banerjee, R (2022). Concomitant clustering and ordering leading to B2+ BCC microstructures in refractory high entropy alloys. Trans Indian Inst Met 75, 907–916.CrossRefGoogle Scholar
De Fontaine, D, Paton, NE & Williams, JC (1971). The omega phase transformation in titanium alloys as an example of displacement controlled reactions. Acta Metall 19, 1153–1162.CrossRefGoogle Scholar
Gorr, B, Azim, M, Christ, HJ, Mueller, T, Schliephake, D & Heilmaier, M (2015). Phase equilibria, microstructure, and high temperature oxidation resistance of novel refractory high-entropy alloys. J Alloys Compd 624, 270–278.CrossRefGoogle Scholar
Gorr, B, Mueller, F, Christ, HJ, Mueller, T, Chen, H, Kauffmann, A & Heilmaier, M (2016). High temperature oxidation behavior of an equimolar refractory metal-based alloy 20Nb-20Mo-20Cr-20Ti-20Al with and without Si addition. J Alloys Compd 688, 468–477.CrossRefGoogle Scholar
Gorr, B, Müller, F, Azim, M, Christ, HJ, Müller, T, Chen, H, Kauffmann, A & Heilmaier, M (2017). High-temperature oxidation behavior of refractory high-entropy alloys: Effect of alloy composition. Oxid Met 88, 333–349.CrossRefGoogle Scholar
Hellman, OC, Vandenbroucke, JA, Rüsing, J, Isheim, D & Seidman, DN (2000). Analysis of three-dimensional atom-probe data by the proximity histogram. Microsc Microanal 6, 437–444.CrossRefGoogle ScholarPubMed
Jensen, JK (2017). Characterization of a High Strength, Refractory High Entropy Alloy, AlMo0.5NbTa0.5TiZr. Columbus: The Ohio State University. Available at http://rave.ohiolink.edu/etdc/view?acc_num=osu1492175560975813Google Scholar
Kadirvel, K, Kloenne, Z, Jensen, JK, Fraser, H & Wang, Y (2021). Phase-field modelling of transformation pathways and microstructural evolution in multi-principal element alloys. Appl Phys Lett 119, 171905.CrossRefGoogle Scholar
Kral, P, Blum, W, Dvorak, J, Yurchenko, N, Stepanov, N, Zherebtsov, S, Kuncicka, L, Kvapilova, M & Sklenicka, V (2020). Creep behavior of an AlTiVNbzr0.25 high entropy alloy at 1073 K. Mater Sci Eng A 783, 139291.CrossRefGoogle Scholar
Larianovsky, N, Katz-Demyanetz, A, Eshed, E & Regev, M (2017). Microstructure, tensile and creep properties of Ta20Nb20Hf20Zr20Ti20 high entropy alloy. Materials 10, 883.CrossRefGoogle ScholarPubMed
Leonard, KJ, Tewari, R, Arya, A, Mishurda, JC, Dey, GK & Vasudevan, VK (2009). Decomposition of the βo phase to the P63/mcm, hP18 structure in Nb-(24-36)Ti-40Al alloys. Acta Mater 57, 4440–4453.CrossRefGoogle Scholar
Miracle, DB & Senkov, ON (2017). A critical review of high entropy alloys and related concepts. Acta Mater 122, 448–511.CrossRefGoogle Scholar
Miracle, DB, Tsai, M-H, Senkov, ON, Soni, V & Banerjee, R (2020). Refractory high entropy superalloys (RSAs). Scr Mater 187, 445–452.CrossRefGoogle Scholar
Porter, DA, Easterling, KE & Sherif, MY (2009). Phase Transformations in Metals and Alloys, 3rd ed. Boca Raton: CRC Press.Google Scholar
Reed, RC (2006). The Superalloys Fundamentals and Applications. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Senkov, ON, Jensen, JK, Pilchak, AL, Miracle, DB & Fraser, HL (2018 a). Compositional variation effects on the microstructure and properties of a refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr. Mater Des 139, 498–511.CrossRefGoogle Scholar
Senkov, ON, Miracle, DB, Chaput, KJ & Couzinie, JP (2018 b). Development and exploration of refractory high entropy alloys – A review. J Mater Res 33, 3092–3128.CrossRefGoogle Scholar
Senkov, ON, Senkova, SV & Woodward, C (2014 a). Effect of aluminum on the microstructure and properties of two refractory high-entropy alloys. Acta Mater 68, 214–228.CrossRefGoogle Scholar
Senkov, ON, Wilks, GB, Miracle, DB, Chuang, CP & Liaw, PK (2010). Refractory high-entropy alloys. Intermetallics 18, 1758–1765.CrossRefGoogle Scholar
Senkov, ON, Woodward, C & Miracle, DB (2014 b). Microstructure and properties of aluminum-containing refractory high-entropy alloys. JOM 66, 2030–2042.CrossRefGoogle Scholar
Singh, AK, Banumathy, S, Sowjanya, D & Rao, MH (2008). On the structure of the B2 phase in Ti-Al-Mo alloys. J Appl Phys 103, 103519.CrossRefGoogle Scholar
Soffa, WA & Laughlin, DE (1989). Decomposition and ordering processes involving thermodynamically first-order order → disorder transformations. Acta Metall 37, 3019–3028. doi:10.1016/0001-6160(89)90338-6CrossRefGoogle Scholar
Soni, V, Gwalani, B, Alam, T, Dasari, S, Zheng, Y, Senkov, ON, Miracle, D & Banerjee, R (2020). Phase inversion in a two-phase, BCC + B2, refractory high entropy alloy. Acta Mater 185, 89–97.CrossRefGoogle Scholar
Soni, V, Gwalani, B, Senkov, ON, Viswanathan, B, Alam, T, Miracle, DB & Banerjee, R (2018 a). Phase stability as a function of temperature in a refractory high-entropy alloy. J Mater Res 33, 3235–3246.CrossRefGoogle Scholar
Soni, V, Senkov, ON, Gwalani, B, Miracle, DB & Banerjee, R (2018 b). Microstructural design for improving ductility of an initially brittle refractory high entropy alloy. Sci Rep 8, 8816.CrossRefGoogle ScholarPubMed
Villars, P & Calvert, LD (1986). Pearson's Handbook of Crystallographic Data for Intermetallic Phases. Materials Park, OH: American Soceity for Metals.Google Scholar
Whitfield, TE, Pickering, EJ, Owen, LR, Senkov, ON, Miracle, DB, Stone, HJ & Jones, NG (2021). An assessment of the thermal stability of refractory high entropy superalloys. J Alloys Compd 857, 157583.CrossRefGoogle Scholar
Williams, JC, de Fontaine, D & Paton, NE (1973). The ω-phase as an example of an unusual shear transformation. Metall Trans 4, 2701–2708.CrossRefGoogle Scholar
Zhan, Y & Pang, M (2015). Bonding characteristics and site occupancies of alloying elements in Zr3Al2 compound from first principles. J Alloys Compd 622, 960–965.CrossRefGoogle Scholar