Faculty Publications
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Item Basic alloying elements used in high-entropy alloys(De Gruyter, 2023) Chandrakar, R.; Sridhar, K.; Sahu, P.S.; Chandraker, S.; Gupta, P.K.The mechanical characteristics of high-entropy alloys (HEAs) can be improved by a variety of alloying elements; however, it is unclear how the alloying of various elements affects the changes in the microstructure and the mechanical properties of HEAs. The alloying elements like Cr, V, Ti, Zr, and Hf regulate the melting temperature, lattice constant, and the mass density of HEAs. The electrical structure and the mechanical characteristics of HEAs are significantly impacted by the valence electron concentration. High VEC can enhance mechanical characteristics while decreasing its ductility. Ti significantly affects ductility, while Cr-alloying significantly affects the mechanical characteristics of HEAs. Our findings offer the fundamental understanding required to direct the development of HEAs with superior mechanical characteristics. © 2023 Walter de Gruyter GmbH, Berlin/Boston. All rights reserved.Item Microstructural and mechanical properties of AlCoCrCuFeNiSix (x = 0 and 0.9) high entropy alloys(Elsevier Ltd, 2021) Chandrakar, R.; Kumar, A.; Chandraker, S.; Rao, K.R.; Chopkar, M.In this work, the effect of addition of Si on the phase evolution and mechanical properties of AlCoCrCuFeNiSix alloy system has been studied. The High Entropy Alloys (x = 0 and 0.9) have been synthesised by powder metallurgy route which includes mechanical alloying (MA) and spark plasma sintering. X-ray diffraction technique was performed to understand the alloying behaviour and to investigate the phase formation of the high entropy alloys. The samples after spark plasma sintering comprised mainly of body centered cubic structured phase with a small extent of face centered cubic structured phase. With the addition of silicon, the XRD peak intensity of body centered cubic appears strong compared to the face centered cubic structured phase. Moreover, no intermetallic is observed in AlCoCrCuFeNi high entropy alloy system. However, further accumulation of Silicon results in the evolution of sigma (?) phase. © 2020 Elsevier LtdItem Phase Evolution of Novel MoNbSiTiW Refractory High-Entropy Alloy Prepared by Mechanical Alloying(Springer, 2022) Prakash, O.; Chandrakar, R.; Chandraker, S.; Rao, K.R.; Kumar, R.; Kumar, A.; Dubey, V.Refractory high-entropy alloys (RHEAs) are new types of material that have been developed for high-temperature applications. RHEAs should have enhanced high-temperature strength while maintaining a sufficient level of room-temperature toughness. The phase evolution of novel MoNbSiTiW RHEAs was investigated after mechanical alloying (MA) for 35 h. X-ray diffraction (XRD) was used to analyze the phase evolution, and analysis of particle morphologies was done using a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). XRD results indicate that NbMoSiTiW RHEAs with up to 10 h of mechanical alloying have a stable solid solution phase with body centered cubic (BCC) structure. Further milling of NbMoSiTiW RHEAs promotes the evolution of intermetallic compounds until 35 h of mechanical alloying. The Williamson-Hall process was incorporated for crystalline size and lattice strain measurement and the results show that, after 35 h of mechanical alloying, the crystalline size decreased from 298 nm to 25 nm, and an enhancement in lattice strain was observed from 0.1% to 0.65%. © 2022, The Minerals, Metals & Materials Society.