Geleneksel sinterleme ve spark plazma sinterleme yöntemlerinin nanokristal yapılı CoCrFeNi yüksek entropili alaşımın mikroyapısal özellikleri ve sertliği üzerine etkilerinin araştırılması
Yıl 2024,
, 2515 - 2524, 20.05.2024
Ali Rıza Baloğlu
,
Mustafa Tekin
,
Hasan Kotan
Öz
CoCrFeNi YEA’ları mekanik alaşımlama yöntemiyle üretilerek geleneksel sinterleme ve spark plazma sinterleme yöntemleriyle konsolide edilmiştir. Sinterleme yöntemi ve sıcaklıklarının bir fonksiyonu olarak mikroyapıların incelenmesi için x-ışınları difraksiyonu (XRD), odaklanmış iyon demeti mikroskobu (FIB) ve geçirimli elektron mikroskobu (TEM) yöntemleri kullanılmıştır. Elde edilen sonuçlar, alaşımlanmış yapıların tek fazlı yüzey merkezli kübik (ymk) kristal yapıya sahip olduğunu göstermiştir. Bununla birlikte, aynı sıcaklıklarda uygulanan spark plazma sinterleme sonrasında alaşımların mikroyapılarında ymk kristal yapıya sahip matris fazına ilave olarak Cr7C3 fazının da oluştuğu tespit edilmiştir. Mekanik alaşımlanmış yapıların tane boyutu 10 nm civarında iken, 1000 ve 1100 °C’deki geleneksel sinterleme sonrasında tane boyutu sırasıyla 450 nm ve 1,5 µm değerlerine ulaşmış, bu da nanokristal yapılı CoCrFeNi alaşımının geleneksel sinterleme ile termal kararlığını koruyamadığını göstermektedir. Mekanik alaşımlanmış tozların spark plazma sinterleme ile 1100 °C’de konsolidasyonu sonrası YEA’nın tane boyutu yaklaşık 355 nm olarak elde edilmiş olup bu değer aynı sıcaklıkta geleneksel sinterleme ile elde edilmiş alaşımın tane boyutundan daha küçüktür. Buna göre, CoCrFeNi YEA’sının mekanik alaşımlama sonrası 4,6 GPa olarak tespit edilen sertliği, 1100 °C’deki geleneksel sinterleme sonrasında görülen tane büyümesi nedeniyle 2,1 GPa’ya düşmüş, ancak 1100 °C’de spark plazma sinterleme ile konsolidasyon sonucunda sertlik değeri 3,6 GPa olarak korunmuştur.
Teşekkür
Bu araştırma, Necmettin Erbakan Üniversitesi Bilimsel Araştırma Projeleri Komisyonu tarafından 181219015 kodlu projeyle kısmen desteklenmiştir. Bu çalışma Prof. Dr. Hasan KOTAN danışmanlığında tamamlanan Ali Rıza BALOĞLU’na ait “Mekanik Alaşımlama ile Üretilen FeCoCrNi Yüksek Entropi Alaşımının Mikroyapı ve Mekanik Özelliklerine Geleneksel Sinterleme ve Spark Plazma Sinterlemenin Etkisinin Araştırılması” isimli yüksek lisans tezi esas alınarak hazırlanmıştır. Ayrıca yazarlar SPS çalışmalarındaki yardımları için Doç. Dr. Erhan AYAS’a teşekkür eder.
Kaynakça
- 1. Miracle D.B., Senkov O.N., A critical review of high entropy alloys and related concepts, Acta Mater., 122, 448-511, 2017.
- 2. Wang J., Guo T., Li J., Jia W., Kou H., Microstructure and mechanical properties of non-equilibrium solidified CoCrFeNi high entropy alloy, Mater. Chem. Phys., 210, 192-196, 2018.
- 3. He J., Wang H., Huang H., Xu X., Chen M., Wu Y., Liu X., Nieh T., An K., Lu Z., A precipitation-hardened high-entropy alloy with outstanding tensile properties, Acta Mater, 102, 187-196, 2016.
- 4. İcin K., Sünbül S.E., Yıldız A., Cantor Yüksek Entropili Alaşımına Mn Yerine Cu İkamesinin Yapısal ve Mekanik Özellikler Üzerindeki Etkisinin Araştırılması, Gazi University Journal of Science Part C: Design and Technology, 11 (2), 379-387, 2023.
- 5. Chanda B., Verma A., Das J., Nano-/ultrafine eutectic in CoCrFeNi (Nb/Ta) high-entropy alloys, Trans. Indian Inst. Met., 71 (11), 2717-2723, 2018.
- 6. Jain R., Rahul M., Jain S., Samal S., Kumar V., Phase evolution and mechanical behaviour of Co–Fe–Mn–Ni–Ti eutectic high entropy alloys, Trans. Indian Inst. Met., 71 (11), 2795-2799, 2018.
- 7. Kotan H., Darling K.A., Isothermal annealing of a thermally stabilized Fe-based ferritic alloy, J. Mater. Eng. Perform., 24 (9), 3271-3276, 2015.
- 8. Pickering E., Muñoz-Moreno R., Stone H., Jones N., Precipitation in the equiatomic high-entropy alloy CrMnFeCoNi, Scr. Mater., 113, 106-109, 2016.
- 9. Tekin M., Polat G., Kotan H., An investigation of abnormal grain growth in Zr doped CoCrFeNi HEAs through in-situ formed oxide phases, Intermetallics, 146, 107588, 2022.
- 10. Zhou Y., Zhang Y., Wang Y., Chen G., Solid solution alloys of AlCoCrFeNiTix with excellent room-temperature mechanical properties, Appl. Phys. Lett., 90 (18), 181904, 2007.
- 11. Senkov O.N., Wilks G., Scott J., Miracle D.B., Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys, Intermetallics, 19 (5), 698-706, 2011.
- 12. Vaidya M., Guruvidyathri K., Murty B., Phase formation and thermal stability of CoCrFeNi and CoCrFeMnNi equiatomic high entropy alloys, J. Alloys Compd., 774, 856-864, 2019.
- 13. Murty B., Ranganathan S., Novel materials synthesis by mechanical alloying/milling, Int. Mater. Rev., 43 (3), 101-141, 1998.
- 14. Sharma A.S., Yadav S., Biswas K., Basu B., High-entropy alloys and metallic nanocomposites: Processing challenges, microstructure development and property enhancement, Mater. Sci. Eng. R Rep., 131, 1-42, 2018.
- 15. Gundes A., Gogebakan M., Nanocrystallization of Al88Ni10Nd2 alloy by mechanical alloying, Gazi University Journal of Science 32 (1), 310-316, 2019.
- 16. Jiang H., Han K., Qiao D., Lu Y., Cao Z., Li T., Effects of Ta addition on the microstructures and mechanical properties of CoCrFeNi high entropy alloy, Mater. Chem. Phys., 210, 43-48, 2018.
- 17. Zhu M., Li K., Liu Y., Wang Z., Yao L., Fa Y., Jian Z., Microstructure, Corrosion Behaviour and Microhardness of Non-equiatomic Fe1.5CoNiCrCux (0.5≤ x≤ 2.0) High-Entropy Alloys, Trans. Indian Inst. Met., 73 (2), 389-397, 2020.
- 18. Vaidya M., Anupam A., Bharadwaj J.V., Srivastava C., Murty B., Grain growth kinetics in CoCrFeNi and CoCrFeMnNi high entropy alloys processed by spark plasma sintering, J. Alloys Compd., 791, 1114-1121, 2019.
- 19. Xie S., Li R., Yuan T., Zhang M., Wang M., Wu H., Zeng F., Viscous flow activation energy adaptation by isothermal spark plasma sintering applied with different current mode, Scr. Mater., 149, 125-128, 2018.
- 20. Deng S., Li R., Yuan T., Xie S., Zhang M., Zhou K., Cao P., Direct current-enhanced densification kinetics during spark plasma sintering of tungsten powder, Scr. Mater., 143, 25-29, 2018.
- 21. Çetinkaya Z., Flash sintering effect on fly ash microstructure, Journal of the Faculty of Engineering and Architecture of Gazi University, 37 (1), 137-144, 2021.
- 22. Liu G., Li R., Yuan T., Zhang M., Zeng F., Spark plasma sintering of pure TiCN: densification mechanism, grain growth and mechanical properties, Int. J. Refract. Met. Hard Mater., 66, 68-75, 2017.
- 23. Zhang M., Yuan T., Li R., Xie S., Wang M., Weng Q., Densification mechanisms and microstructural evolution during spark plasma sintering of boron carbide powders, Ceram. Int., 44 (4), 3571-3579, 2018.
- 24. Omori M., Sintering, consolidation, reaction and crystal growth by the spark plasma system (SPS), Mater. Sci. Eng. A, 287 (2), 183-188, 2000.
- 25. Vaidya M., Muralikrishna G.M., Murty B.S., High-entropy alloys by mechanical alloying: A review, J. Mater. Res., 34 (5), 664-686, 2019.
- 26. Vaidya M., Karati A., Marshal A., Pradeep K., Murty B., Phase evolution and stability of nanocrystalline CoCrFeNi and CoCrFeMnNi high entropy alloys, J. Alloys Compd., 770, 1004-1015, 2019.
- 27. John R., Karati A., Garlapati M.M., Vaidya M., Bhattacharya R., Fabijanic D., Murty B., Influence of mechanically activated annealing on phase evolution in Al₀. ₃CoCrFeNi high-entropy alloy, J. Mater. Sci., 54, 14588-14598, 2019.
- 28. Zaddach A., Niu C., Oni A., Fan M., LeBeau J., Irving D., Koch C., Structure and magnetic properties of a multi-principal element Ni–Fe–Cr–Co–Zn–Mn alloy, Intermetallics, 68, 107-112, 2016.
- 29. Vaidya M., Pradeep K., Murty B., Wilde G., Divinski S., Bulk tracer diffusion in CoCrFeNi and CoCrFeMnNi high entropy alloys, Acta Mater., 146, 211-224, 2018.
- 30. Dutta G., Bose D., Effect of sintering temperature on density, porosity and hardness of a powder metallurgy component, Int. j. emerg. technol. adv. eng., 2 (8), 121-123, 2012.
- 31. Shongwe M.B., Diouf S., Durowoju M.O., Olubambi P.A., Effect of sintering temperature on the microstructure and mechanical properties of Fe–30% Ni alloys produced by spark plasma sintering, J. Alloys Compd., 649, 824-832, 2015.
- 32. Fu Z., Chen W., Xiao H., Zhou L., Zhu D., Yang S., Fabrication and properties of nanocrystalline Co0.5FeNiCrTi0.5 high entropy alloy by MA–SPS technique, Mater. Des., 44, 535-539, 2013.
- 33. Teber A., Schoenstein F., Têtard F., Abdellaoui M., Jouini N., Effect of SPS process sintering on the microstructure and mechanical properties of nanocrystalline TiC for tools application, Int. J. Refract. Met. Hard Mater., 30 (1), 64-70, 2012.
- 34. Rahaman M.N., Ceramic processing and sintering, CRC press2017.
- 35. Tekin M., Kotan H., Microstructural Characterization and Hardness Study of Nanostructured CoCrFeNi High Entropy Alloys with Dual Effect of Y and Nano-Sized Y2O3 Additions, Trans. Indian Inst. Met., 75, 2389-2394, 2022.
- 36. Langford J.I., Wilson A., Scherrer after sixty years: a survey and some new results in the determination of crystallite size, J. Appl. Crystallogr., 11 (2), 102-113, 1978.
- 37. Garlapati M.M., Vaidya M., Karati A., Mishra S., Bhattacharya R., Murty B., Influence of Al content on thermal stability of nanocrystalline AlxCoCrFeNi high entropy alloys at low and intermediate temperatures, Adv. Powder Technol., 31 (5), 1985-1993, 2020.
- 38. Cullity B.D., Elements of X-ray Diffraction, Addison-Wesley Publishing, 1956.
- 39. Kotan H., Thermal stability, phase transformation and hardness of mechanically alloyed nanocrystalline Fe-18Cr-8Ni stainless steel with Zr and Y2O3 additions, J. Alloys Compd., 749, 948-954, 2018.
- 40. Sathiyamoorthi P., Basu J., Kashyap S., Pradeep K., Kottada R.S., Thermal stability and grain boundary strengthening in ultrafine-grained CoCrFeNi high entropy alloy composite, Mater. Des., 134, 426-433, 2017.
- 41. Fan R., Wang L., Zhao L.,. Wang L, Zhao S., Zhang Y., Cui B., Synergistic effect of Nb and Mo alloying on the microstructure and mechanical properties of CoCrFeNi high entropy alloy, Mater. Sci. Eng. A, 829, 142153, 2022.
- 42. Phaneuf M., Applications of focused ion beam microscopy to materials science specimens, Micron, 30 (3), 277-288, 1999.
- 43. Liu F., Kirchheim R., Grain boundary saturation and grain growth, Scr. Mater., 51 (6), 521-525, 2004.
- 44. Driver J., Stability of nanostructured metals and alloys, Scr. Mater., 51 (8), 819-823, 2004.
- 45. Praveen S., Basu J., Kashyap S., Kottada R.S., Exceptional resistance to grain growth in nanocrystalline CoCrFeNi high entropy alloy at high homologous temperatures, J. Alloys Compd., 662, 361-367, 2016.
- 46. Li M., Guo Y., Wang H., Shan J., Chang Y., Microstructures and mechanical properties of oxide dispersion strengthened CoCrFeNi high-entropy alloy produced by mechanical alloying and spark plasma sintering, Intermetallics, 123, 106819, 2020.
- 47. Hadorn J.P., Hantzsche K., Yi S., Bohlen J., Letzig D., Agnew S.R., Effects of solute and second-phase particles on the texture of Nd-containing Mg alloys, Metall. Mater. Trans. A, 43 (4), 1363-1375, 2012.
- 48. Polat G., Teki̇n M., Kotan H., Role of yttrium addition and annealing temperature on thermal stability and hardness of nanocrystalline CoCrFeNi high entropy alloy, Intermetallics, 146, 107589, 2022.
- 49. Rohrer G.S., Introduction to Grains, Phases, and Interfaces—an Interpretation of Microstructure, Trans. AIME, 1948, 175, 15–51, by Smith C.S., Metall. Mater. Trans. B, 41 (3), 457-494, 2010.
- 50. Kotan H., Darling K.A., Scattergood R.O., Koch C.C., Influence of Zr and nano-Y2O3 additions on thermal stability and improved hardness in mechanically alloyed Fe base ferritic alloys, J. Alloys Compd., 615, 1013-1018, 2014.
Investigation of the effects of conventional sintering and spark plasma sintering methods on the microstructural properties and hardness of nanostructured CoCrFeNi high entropy alloy
Yıl 2024,
, 2515 - 2524, 20.05.2024
Ali Rıza Baloğlu
,
Mustafa Tekin
,
Hasan Kotan
Öz
In the present study, CoCrFeNi HEAs were prepared in nanocrystalline structure and consolidated via conventional sintering and spark plasma sintering. Investigation of microstructures were implemented by using x-ray diffraction (XRD), focused ion beam microscopy (FIB), and transmission electron microscopy (TEM) with respect to sintering type and temperature. The findings have showed that the as-milled single-phase face centered cubic (fcc) crystal structure was retained after conventional sintering at 1000 and 1100 °C, whereas spark plasma sintering yielded additional phase (Cr7C3) at the same temperatures. The as-milled grain size was increased from 10 nm to 450 nm and 1.5 µm after conventional sintering at 1000 and 1100 °C, respectively, revealing that the nano-structured CoCrFeNi alloy does not remain thermally stable after long exposures at elevated temperatures. On the other hand, the grain size was retained around 353 nm after spark plasma sintering at 1100 °C, which is dramatically smaller than that of conventional sintering. Accordingly, the hardness of mechanically alloyed CoCrFeNi HEA reduced from 4.6 GPa to 2.1 GPa after conventional sintering at 1100 °C due to the significant grain growth, whereas the advanced hardness of 3.6 GPa was maintained after consolidation at the same temperature with spark plasma sintering.
Kaynakça
- 1. Miracle D.B., Senkov O.N., A critical review of high entropy alloys and related concepts, Acta Mater., 122, 448-511, 2017.
- 2. Wang J., Guo T., Li J., Jia W., Kou H., Microstructure and mechanical properties of non-equilibrium solidified CoCrFeNi high entropy alloy, Mater. Chem. Phys., 210, 192-196, 2018.
- 3. He J., Wang H., Huang H., Xu X., Chen M., Wu Y., Liu X., Nieh T., An K., Lu Z., A precipitation-hardened high-entropy alloy with outstanding tensile properties, Acta Mater, 102, 187-196, 2016.
- 4. İcin K., Sünbül S.E., Yıldız A., Cantor Yüksek Entropili Alaşımına Mn Yerine Cu İkamesinin Yapısal ve Mekanik Özellikler Üzerindeki Etkisinin Araştırılması, Gazi University Journal of Science Part C: Design and Technology, 11 (2), 379-387, 2023.
- 5. Chanda B., Verma A., Das J., Nano-/ultrafine eutectic in CoCrFeNi (Nb/Ta) high-entropy alloys, Trans. Indian Inst. Met., 71 (11), 2717-2723, 2018.
- 6. Jain R., Rahul M., Jain S., Samal S., Kumar V., Phase evolution and mechanical behaviour of Co–Fe–Mn–Ni–Ti eutectic high entropy alloys, Trans. Indian Inst. Met., 71 (11), 2795-2799, 2018.
- 7. Kotan H., Darling K.A., Isothermal annealing of a thermally stabilized Fe-based ferritic alloy, J. Mater. Eng. Perform., 24 (9), 3271-3276, 2015.
- 8. Pickering E., Muñoz-Moreno R., Stone H., Jones N., Precipitation in the equiatomic high-entropy alloy CrMnFeCoNi, Scr. Mater., 113, 106-109, 2016.
- 9. Tekin M., Polat G., Kotan H., An investigation of abnormal grain growth in Zr doped CoCrFeNi HEAs through in-situ formed oxide phases, Intermetallics, 146, 107588, 2022.
- 10. Zhou Y., Zhang Y., Wang Y., Chen G., Solid solution alloys of AlCoCrFeNiTix with excellent room-temperature mechanical properties, Appl. Phys. Lett., 90 (18), 181904, 2007.
- 11. Senkov O.N., Wilks G., Scott J., Miracle D.B., Mechanical properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 refractory high entropy alloys, Intermetallics, 19 (5), 698-706, 2011.
- 12. Vaidya M., Guruvidyathri K., Murty B., Phase formation and thermal stability of CoCrFeNi and CoCrFeMnNi equiatomic high entropy alloys, J. Alloys Compd., 774, 856-864, 2019.
- 13. Murty B., Ranganathan S., Novel materials synthesis by mechanical alloying/milling, Int. Mater. Rev., 43 (3), 101-141, 1998.
- 14. Sharma A.S., Yadav S., Biswas K., Basu B., High-entropy alloys and metallic nanocomposites: Processing challenges, microstructure development and property enhancement, Mater. Sci. Eng. R Rep., 131, 1-42, 2018.
- 15. Gundes A., Gogebakan M., Nanocrystallization of Al88Ni10Nd2 alloy by mechanical alloying, Gazi University Journal of Science 32 (1), 310-316, 2019.
- 16. Jiang H., Han K., Qiao D., Lu Y., Cao Z., Li T., Effects of Ta addition on the microstructures and mechanical properties of CoCrFeNi high entropy alloy, Mater. Chem. Phys., 210, 43-48, 2018.
- 17. Zhu M., Li K., Liu Y., Wang Z., Yao L., Fa Y., Jian Z., Microstructure, Corrosion Behaviour and Microhardness of Non-equiatomic Fe1.5CoNiCrCux (0.5≤ x≤ 2.0) High-Entropy Alloys, Trans. Indian Inst. Met., 73 (2), 389-397, 2020.
- 18. Vaidya M., Anupam A., Bharadwaj J.V., Srivastava C., Murty B., Grain growth kinetics in CoCrFeNi and CoCrFeMnNi high entropy alloys processed by spark plasma sintering, J. Alloys Compd., 791, 1114-1121, 2019.
- 19. Xie S., Li R., Yuan T., Zhang M., Wang M., Wu H., Zeng F., Viscous flow activation energy adaptation by isothermal spark plasma sintering applied with different current mode, Scr. Mater., 149, 125-128, 2018.
- 20. Deng S., Li R., Yuan T., Xie S., Zhang M., Zhou K., Cao P., Direct current-enhanced densification kinetics during spark plasma sintering of tungsten powder, Scr. Mater., 143, 25-29, 2018.
- 21. Çetinkaya Z., Flash sintering effect on fly ash microstructure, Journal of the Faculty of Engineering and Architecture of Gazi University, 37 (1), 137-144, 2021.
- 22. Liu G., Li R., Yuan T., Zhang M., Zeng F., Spark plasma sintering of pure TiCN: densification mechanism, grain growth and mechanical properties, Int. J. Refract. Met. Hard Mater., 66, 68-75, 2017.
- 23. Zhang M., Yuan T., Li R., Xie S., Wang M., Weng Q., Densification mechanisms and microstructural evolution during spark plasma sintering of boron carbide powders, Ceram. Int., 44 (4), 3571-3579, 2018.
- 24. Omori M., Sintering, consolidation, reaction and crystal growth by the spark plasma system (SPS), Mater. Sci. Eng. A, 287 (2), 183-188, 2000.
- 25. Vaidya M., Muralikrishna G.M., Murty B.S., High-entropy alloys by mechanical alloying: A review, J. Mater. Res., 34 (5), 664-686, 2019.
- 26. Vaidya M., Karati A., Marshal A., Pradeep K., Murty B., Phase evolution and stability of nanocrystalline CoCrFeNi and CoCrFeMnNi high entropy alloys, J. Alloys Compd., 770, 1004-1015, 2019.
- 27. John R., Karati A., Garlapati M.M., Vaidya M., Bhattacharya R., Fabijanic D., Murty B., Influence of mechanically activated annealing on phase evolution in Al₀. ₃CoCrFeNi high-entropy alloy, J. Mater. Sci., 54, 14588-14598, 2019.
- 28. Zaddach A., Niu C., Oni A., Fan M., LeBeau J., Irving D., Koch C., Structure and magnetic properties of a multi-principal element Ni–Fe–Cr–Co–Zn–Mn alloy, Intermetallics, 68, 107-112, 2016.
- 29. Vaidya M., Pradeep K., Murty B., Wilde G., Divinski S., Bulk tracer diffusion in CoCrFeNi and CoCrFeMnNi high entropy alloys, Acta Mater., 146, 211-224, 2018.
- 30. Dutta G., Bose D., Effect of sintering temperature on density, porosity and hardness of a powder metallurgy component, Int. j. emerg. technol. adv. eng., 2 (8), 121-123, 2012.
- 31. Shongwe M.B., Diouf S., Durowoju M.O., Olubambi P.A., Effect of sintering temperature on the microstructure and mechanical properties of Fe–30% Ni alloys produced by spark plasma sintering, J. Alloys Compd., 649, 824-832, 2015.
- 32. Fu Z., Chen W., Xiao H., Zhou L., Zhu D., Yang S., Fabrication and properties of nanocrystalline Co0.5FeNiCrTi0.5 high entropy alloy by MA–SPS technique, Mater. Des., 44, 535-539, 2013.
- 33. Teber A., Schoenstein F., Têtard F., Abdellaoui M., Jouini N., Effect of SPS process sintering on the microstructure and mechanical properties of nanocrystalline TiC for tools application, Int. J. Refract. Met. Hard Mater., 30 (1), 64-70, 2012.
- 34. Rahaman M.N., Ceramic processing and sintering, CRC press2017.
- 35. Tekin M., Kotan H., Microstructural Characterization and Hardness Study of Nanostructured CoCrFeNi High Entropy Alloys with Dual Effect of Y and Nano-Sized Y2O3 Additions, Trans. Indian Inst. Met., 75, 2389-2394, 2022.
- 36. Langford J.I., Wilson A., Scherrer after sixty years: a survey and some new results in the determination of crystallite size, J. Appl. Crystallogr., 11 (2), 102-113, 1978.
- 37. Garlapati M.M., Vaidya M., Karati A., Mishra S., Bhattacharya R., Murty B., Influence of Al content on thermal stability of nanocrystalline AlxCoCrFeNi high entropy alloys at low and intermediate temperatures, Adv. Powder Technol., 31 (5), 1985-1993, 2020.
- 38. Cullity B.D., Elements of X-ray Diffraction, Addison-Wesley Publishing, 1956.
- 39. Kotan H., Thermal stability, phase transformation and hardness of mechanically alloyed nanocrystalline Fe-18Cr-8Ni stainless steel with Zr and Y2O3 additions, J. Alloys Compd., 749, 948-954, 2018.
- 40. Sathiyamoorthi P., Basu J., Kashyap S., Pradeep K., Kottada R.S., Thermal stability and grain boundary strengthening in ultrafine-grained CoCrFeNi high entropy alloy composite, Mater. Des., 134, 426-433, 2017.
- 41. Fan R., Wang L., Zhao L.,. Wang L, Zhao S., Zhang Y., Cui B., Synergistic effect of Nb and Mo alloying on the microstructure and mechanical properties of CoCrFeNi high entropy alloy, Mater. Sci. Eng. A, 829, 142153, 2022.
- 42. Phaneuf M., Applications of focused ion beam microscopy to materials science specimens, Micron, 30 (3), 277-288, 1999.
- 43. Liu F., Kirchheim R., Grain boundary saturation and grain growth, Scr. Mater., 51 (6), 521-525, 2004.
- 44. Driver J., Stability of nanostructured metals and alloys, Scr. Mater., 51 (8), 819-823, 2004.
- 45. Praveen S., Basu J., Kashyap S., Kottada R.S., Exceptional resistance to grain growth in nanocrystalline CoCrFeNi high entropy alloy at high homologous temperatures, J. Alloys Compd., 662, 361-367, 2016.
- 46. Li M., Guo Y., Wang H., Shan J., Chang Y., Microstructures and mechanical properties of oxide dispersion strengthened CoCrFeNi high-entropy alloy produced by mechanical alloying and spark plasma sintering, Intermetallics, 123, 106819, 2020.
- 47. Hadorn J.P., Hantzsche K., Yi S., Bohlen J., Letzig D., Agnew S.R., Effects of solute and second-phase particles on the texture of Nd-containing Mg alloys, Metall. Mater. Trans. A, 43 (4), 1363-1375, 2012.
- 48. Polat G., Teki̇n M., Kotan H., Role of yttrium addition and annealing temperature on thermal stability and hardness of nanocrystalline CoCrFeNi high entropy alloy, Intermetallics, 146, 107589, 2022.
- 49. Rohrer G.S., Introduction to Grains, Phases, and Interfaces—an Interpretation of Microstructure, Trans. AIME, 1948, 175, 15–51, by Smith C.S., Metall. Mater. Trans. B, 41 (3), 457-494, 2010.
- 50. Kotan H., Darling K.A., Scattergood R.O., Koch C.C., Influence of Zr and nano-Y2O3 additions on thermal stability and improved hardness in mechanically alloyed Fe base ferritic alloys, J. Alloys Compd., 615, 1013-1018, 2014.