Cold rolling of high entropy alloy and investigation of mechanical proeprties.pptx

Cold rolling was done on the cantor alloy to better understand and investigate the characteristics of HEAs, and a breakthrough reduction ratio of 99% was reached. from 3 mm to 0.044 mm. The original sample is created utilising the PAAM operation. The cold rolling operation is done in four phases, with the initial sample rolled from 3mm to 0.36mm. The second sage moved from 0.36mm to 0.2mm. 3rd = 0.2 to 0.12mm; in the first step, 0.12mm was treated at 750C before being reduced to 0.044mm using the sandwich process. The UTM findings are linked to the ppt.

1. MMMB940:Advanced Project Seminar presentation on, “ Fabrication of high/medium entropy alloy thin foils via rolling operation and investigations of their mechanical property” Student Name Student Id Viraj Solankure 7309296 Master of Engineering (Mechanical Engineering) Under the supervision of Dr Lihong Su FACULTY OF ENGINEERING AND INFORMATION SCIENCES

2. Introduction to High entropy alloys: High entropy alloys are those with five or more primary elements and equal atom percentage. Each major element should have a concentration of 5 and 35 atom%. This discovery was done by scientists Yeh J.W and K H huang In 1996. The term high entropy alloys is officially coined after a significant research done by Jien-wei and Brain cantor in 2004, Both scientists described their own concepts as “High Entropy Alloy” by Jien-wei , “ Equiatomic FeCrMnNiCo ” by cantor. The idea behind HEAs to create alloys with a high configurational entropy resulting from the mixing of multiple elements, leading to unique and desirable properties. ∆ Hmix between -10KJ/mol and 5KJ/mol ∆ Sconf >1.5 R Difference in atomic radii ∂ <6.6% [1] Fig.1 CoCrFeMnNi FCC HEA [1]

3. literature Review: Difference between conventional alloys and high entropy alloys: Different High Entropy alloys: High-entropy alloys with Δ Smix , ideal ≧ 1.61R for alloys containing more than five primary elements. Medium-entropy alloys (MEAs) with 1.61R ≧ Δ Smix , ideal ≧ 0.69R for alloys containing two to four primary elements. Low-entropy alloys (LEAs) with Δ Smix , ideal ≦ 0.69R for traditional alloys[2]. Conventional Alloys high entropy alloys Primarily based on one main element, for instance Fe. Composed of five or more principal elements in equal atomic percentage. Small amount of other elements added to achieve desired properties. Tend to form simple solid solutions, FCC and BCC. Often have complex phases and microstructures. High configurational entropy leads to stabilized single-phase structures. Extensively researched established processing methods. New research area with promising applications in high stress, high temperature environments. Figure 2 Value of the ΔSmix for Ternary alloy= 1.39R, quinary alloy= 1.61R, Senary alloy=1.79R [2]

4. Properties of HEAs: Mechanical properties of HEAs High strength good fracture toughness Good creep strength good wear resistance excellent corrosion resistance high thermal stability Thermal properties: Thermal stability Thermal conductivity Coefficient of thermal conductivity Cryogenic stability Chemical Properties Complex Composition High Mixing entropy Solid solution strengthen Phase stability Corrosion resistance Tunable properties Figure 3 | Ashby map of fracture toughness versus yield strength for various classes of materials[3]

5. Applications of HEAs HEAs Application FeCoNiCrMn structure components in high-stress environments   aerospace and automotive parts   Corrosion-resistant coating and components   high temperature and cryogenic applications     FeCoNiCr high strength and high ductility materials   Wear-resistant coatings   chemical processing equipment     FeCoNiCrMo High-strength and high-corrosion-resistant applications   Chemical and petrochemical processing equipment   Nuclear and marine applications     CoCrNi Medical implants and devices   Power generation and chemical processing equipment     FeNiCr Heat-resistant components   Chemical processing equipment   Electrical heating elements

6. Fig. 4 Applications of HEAs [3] Applications of HEAs:

7. Cold Rolling of HEAs: Cold rolling is a typical processing method for high entropy alloys to deform and refine their microstructure. In the cold rolling operation of HEAs, the material is subjected to plastic deformation at room temperature, resulting in changes in its mechanical characteristics and microstructure. The Cantor alloy typically consists of five principal elements: iron(Fe), manganese (Mn), cobalt(Co), chromium(Cr), and nickel(Ni). It is also known for its single-phase Face centered cubic(FCC) Structure which contributes to its high fracture toughness, With the peculiar property that exhibits a unique temperature dependent relationship between strength and ductility, with both properties improving as the temperature decreases. Reduction Ratio: The reduction ratio in rolling process is typically calculated as the initial thickness of the material divided by the final thickness after rolling for example, if an HEA with an initial thickness of 15 mm is rolled to a final thickness of 0.5 mm, then RR can be calculated as, (15-0.5)/15= 0.9666*100= 96.66%

8. Cold rolling operation of Cantor alloy and significance of reduction ratio: Mechanical properties Impact of reduction ratio Strength Increase in yield strength: due to the deformation-induced strengthening mechanisms such as dislocation density increases and grain refinement. Enhanced ultimate tensile strength: It has been seen that UTS increases due to more refined microstructure. Ductility and hardness Elongation reduction: the elongation percentage of the alloy may decrease as the reduction ratio increases due to strain hardening effect caused by cold rolling Increase in hardness: due to the deformation induced changes in the microstructure, such as dislocation accumulation and grain refinement Microstructure Grain refinement: The finer microstructure enhances the strength and hardness of alloy but reduces ductility Dislocation density: Due to the cold rolling contribution two strengthening of cantor alloy it may increase dislocation density that impacts the potential brittleness of material

9. Fig.5 Relationship between reduction ratio and mechanical Properties[6-14] Cold rolling operation of Cantor alloy and significance of reduction ratio:

10. Clear problem definition and objective of research: Research focus The conventional research on HEAs is more concentrated on material composition and its effects on properties , however limited research has been conducted on maximizing the achievable reduction ratio during cold rolling and its impact on other properties of the alloy. Goal of project The goal of the project is to cold roll the following high/medium entropy alloys with high reduction ratios of up to 95–99% and beyond without fracturing or brittle damage , and to verify their corresponding mechanical properties , yield strength, and ultimate tensile strength using a universal tensile testing machine Challenges and considerations As per the previous researchers, there are some factors that we must consider while dealing with this experimentation, increased rolling force, roll deflection . Challenges that we may face are edge cracking, surface finish tension and wrinkling .

11. Fig. 5 FeCoNiCrMn alloy was fabricated using Powder-bed Arc Additive Manufacturing (PAAM) method Material Preparation: Methodology:

12. Base - steel As-built FeCoNiCrMn Through thickness element composition distribution Material preparation continue… Fig.6 Sample 3mm

13. Base - steel As-built FeCoNiCrMn Through thickness hardness distribution of the as-built alloy Material preparation continue… Fig.7 Sample 3mm

14. As-built As-rolled ④ ① ② ③ BD TD ND ① ② ③ ④ TD-BD BD-TD BD-ND ND-TD ① Cold rolling was performed in the following 4 directions. Rolling reduction was 87.5% for all four cases. As-rolled As-built Material preparation continue… Fig.7 Sample 3mm cantor alloy stress-strain curve.

15. As-built As-rolled As-built As-rolled As-built As-built As-rolled As-rolled Material preparation-UTM results

16. ④ ② ③ ① Fig. 8 Open: as-built; Solid fill: as-rolled. Material preparation-UTM results

17. Rolling Operation : Fig 8. Sandwich operation Fig 9. Wrinkling

18. UTM Results: Sample Stress Strain PAAM-0.36-750˚C 775Mpa 0.5066 PAAM-0.12-750˚C 810Mpa 0.3342 As cast-0.36 1500Mpa 0.1170

19. ‌References: S. Wang, “Atomic Structure Modeling of Multi-Principal-Element Alloys by the Principle of Maximum Entropy,”  Entropy , vol. 15, no. 12, pp. 5536–5548, Dec. 2013, doi : https://doi.org/10.3390/e15125536. N. Kaushik, A. Meena, and H. S. Mali, “High entropy alloy synthesis, characterisation , manufacturing & potential applications: a review,” Materials and Manufacturing Processes, pp. 1–25, Dec. 2021, doi : https://doi.org/10.1080/10426914.2021.2006223 B. Gludovatz   et al. , “Exceptional damage-tolerance of a medium-entropy alloy CrCoNi at cryogenic temperatures,”  Nature Communications , vol. 7, no. 1, Feb. 2016, doi : https://doi.org/10.1038/ncomms10602 . X. S. Liu, R. Li, Y. Lu, Y. F. Zhang, P. Yu, and G. Li, “Spinodal decomposition induced nanoprecipitates strengthened CoCrNi -base medium entropy alloy,” Materials Science and Engineering: A, vol. 822, pp. 141674–141674, Aug. 2021, doi : https://doi.org/10.1016/j.msea.2021.141674 M. Kang, Jong Woo Won, J. Kwon, and Young Sang Na, “Intermediate strain rate deformation behavior of a CoCrFeMnNi high-entropy alloy,” Materials Science and Engineering: A, vol. 707, pp. 16–21, Nov. 2017, doi : https://doi.org/10.1016/j.msea.2017.09.026 . Q. Wang et al., “Hierarchical precipitates facilitate the excellent strength-ductility synergy in a CoCrNi -based medium-entropy alloy,” Materials Science and Engineering: A, vol. 873, pp. 145036–145036, May 2023, doi : https://doi.org/10.1016/j.msea.2023.14503 6 Y. Yan, G.-R. Li, W. Ren, H. Wang, and L. Gao, “Effects of hot rolling on microstructure and properties of FeCoNi1.5CrCu/2024Al composites,” Journal of Alloys and Compounds, vol. 900, pp. 163393–163393, Apr. 2022, doi : https://doi.org/10.1016/j.jallcom.2021.163393 Z. Li et al., “Effect of Annealing Temperature on Microstructure and Mechanical Properties of a Severe Cold-Rolled FeCoCrNiMn High-Entropy Alloy,” Metallurgical and Materials Transactions A, vol. 50, no. 7, pp. 3223–3237, Apr. 2019, doi : https://doi.org/10.1007/s11661- 019-05231-y ‌

20. 9. Y. Wu, K. Luo, Y. Zhang, C. Kong, and H. Yu, “Microstructures and mechanical properties of a CoCrFeNiMn high-entropy alloy obtained by 223 K cryorolling and subsequent annealing,” Journal of Alloys and Compounds, vol. 921, p. 166166, Nov. 2022, doi : https://doi.org/10.1016/j.jallcom.2022.166166 . 10. J. Saha and P. P. Bhattacharjee, “Influences of Thermomechanical Processing by Severe Cold and Warm Rolling on the Microstructure, Texture, and Mechanical Properties of an Equiatomic CoCrNi Medium-Entropy Alloy,” Journal of Materials Engineering and Performance, vol. 30, no. 12, pp. 8956–8971, Aug. 2021, doi : https://doi.org/10.1007/s11665-021-06092-6 . 11. A. Semenyuk , M. Klimova , D. Shaysultanov , G. Salishchev , S. Zherebtsov , and N. Stepanov, “Effect of nitrogen on microstructure and mechanical properties of the CoCrFeMnNi high-entropy alloy after cold rolling and subsequent annealing,” Journal of Alloys and Compounds, vol. 888, p. 161452, Dec. 2021, doi : https://doi.org/10.1016/j.jallcom.2021.161452 12. X. Liu et al., “Achieving ultrahigh strength in CoCrNi -based medium-entropy alloys with synergistic strengthening effect,” Materials Science and Engineering: A, vol. 776, p. 139028, Mar. 2020, doi : https://doi.org/10.1016/j.msea.2020.139028 13. S. Paul, B. Tripathy, R. Saha, and P. P. Bhattacharjee, “Microstructure and texture of heavily cold-rolled and annealed extremely low stacking fault energy Cr26Mn20Fe20Co20Ni14 high entropy alloy: Comparative insights,” Journal of Alloys and Compounds, vol. 930, pp. 167418– 167418, Jan. 2023, doi : https://doi.org/10.1016/j.jallcom.2022.167418 14. Z. Zhang, J. Gu, and M. Song, “Precipitation behaviors and mechanical properties of a coldrolled equiatomic FeCoCrNiMn high entropy alloy after long-time annealing treatment at 500 °C,” Materials Letters, vol. 333, pp. 133681–133681, Feb. 2023, doi : https://doi.org/10.1016/j.matlet.2022.133681.