Effects of precipitation hardening heat treatment conditions on the microstructure, mechanical properties, and electrical conductivity of Cu - 0.4%Cr alloy

Document Type : Original Articles

Authors

• Vahid Norouzifard ¹
• amir talebi ²

¹ Department of mechanical engineering, Jundi-shapur University of technology, Dezful, Iran.

² Faculty of Materials & Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran

10.22067/jmme.2022.72467.1026

Abstract

In this paper, the effects of the aging temperature on the microstructure, mechanical properties, and electrical conductivity of Cu-0.4% Cr are investigated. The solid solution treatment was performed at 950 ᵒC for 1 hour. Then the samples were aged 5 hours at 200, 300, 400, 500, and 600 ᵒC. The microstructure of the samples was surveyed using FESEM. An analytical model is also developed to predict the age-hardened samples yield stress and the precipitation of the alloying elements based on the microstructure images analysis and electrical conductivity of the samples. Increasing the aging temperature up to 500 ᵒC, the number of precipitates increases and their size decreases. Yield strength, tensile strength, and work hardening exponent at aging temperatures of 200 and 300 ᵒC decreases a little and increases at 400 and 500 ᵒC and then decreases at higher temperatures. In optimum precipitation hardening conditions, the yield strength and tensile strength are higher 51.7 and 21.7% than solid solution treatment, respectively. Electrical conductivity increases by the aging temperature increasing up to 500 ᵒC and then remains almost constant at higher temperatures. Comparison between the tensile test and the present model results shows that the model is capable to predict the yield strength of the age hardened samples by good accuracy.

Keywords

• Precipitation hardening
• Microstructure
• Mechanical properties
• Analytical model
• Electrical Conductivity

20.1001.1.20087462.1401.33.2.3.3

Main Subjects

• Mechanical Metallurgy

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References

1. Lu, D. P., Wang, J., Zeng, W. J., Liu, Y., Lu, L., and De Sun, B., “Study on high-strength and high-conductivity Cu-Fe-P alloys,” Materials Science and Engineering A, Vol. 421, No. 1–2, pp. 254–259, (2006).
2. Chen, X., Jiang, F., Jiang, J., Xu, P., Tong, M., and Tang, Z., “Precipitation, recrystallization, and evolution of annealing twins in a Cu-Cr-Zr alloy,” Metals (Basel)., Vol. 8, No. 4, pp. 1–15, (2018).
3. Liu, Q., Zhang, X., Ge, Y., Wang, J., and Cui, J. Z., “Effect of processing and heat treatment on behavior of Cu-Cr-Zr alloys to railway contact wire,” Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, Vol. 37, No. 11, pp. 3233–3238, (2006).
4. Hatakeyama, M. et al., “3D-AP and positron annihilation study of precipitation behavior in Cu-Cr-Zr alloy,” Journal of Nuclear Materials, Vol. 386–388, No. C, pp. 852–855, (2009).
5. Suvorova, A. A., Danilov, I. V., Kalinin, G. M., and Korostelev, A. B., “Heat treatment effects on the microstructure and properties of Cu–Cr–Zr alloy used for the ITER blanket components,” Nuclear Materials and Energy, Vol. 15, No. November 2017, pp. 80–84, (2018).
6. Su, J. H., Dong, Q. M., Liu, P., Li, H. J., and Kang, B. X., “Research on aging precipitation in a Cu-Cr-Zr-Mg alloy,” Materials Science and Engineering A, Vol. 392, No. 1–2, pp. 422–426, (2005).
7. Tang, N. Y., Taplin, D. M. R., and Dunlop, G. L., “Precipitation and aging in high-conductivity Cu–Cr alloys with additions of zirconium and magnesium,” Materials Science and Technology, Vol. 1, No. 4, pp. 270–275, (1985).
8. Zhou, H. T., Zhong, J. W., Zhou, X., Zhao, Z. K., and Li, Q. B., “Microstructure and properties of Cu-1.0Cr-0.2Zr-0.03Fe alloy,” Materials Science and Engineering A, Vol. 498, No. 1–2, pp. 225–230, (2008).
9. Shuai, G. W., Fang, P., and Liu, Z. M., “Effects of Fe and P additions on microstructures and properties of Cu-Cr-Zr resistance spot welding electrode alloy,” Applied Mechanics and Materials., Vol. 651–653, pp. 20–23, (2014).
10. Huang, F. X., “Microsture and Properties of a Cu-Cr-Zr-Fe-Ti Alloy,” Applied Mechanics and Materials., Vol. 723, pp. 556–560, (2015).
11. Zhang, Y. et al., “Aging behavior and precipitates analysis of the Cu-Cr-Zr-Ce alloy,” Materials Science and Engineering A, Vol. 650, pp. 248–253, (2016).
12. Li, M. et al., “Microstructures and mechanical properties of the novel CuCrZrFeTiY alloy for fusion reactor,” Journal of Nuclear Materials., Vol. 532, p. 152063, (2020).
13. Fernee, H., Nairn, J., and Atrens, A., “Precipitation hardening of Cu-Fe-Cr alloys Part I Mechanical and electrical properties,” Journal of Materials Science., Vol. 6, No. 36, pp. 2711–2719, (2001).
14. Gao, N., Huttunen-Saarivirta, E., Tiainen, T., and Hemmilä, M., “Influence of prior deformation on the age hardening of a phosphorus- containing Cu-0.61wt.%Cr alloy,” Materials Science and Engineering A, Vol. 342, No. 1–2, pp. 270–278, (2003).
15. Guo, F. A., Xiang, C. J., Yang, C. X., Cao, X. M., Mu, S. G., and Tang, Y. Q., “Study of rare earth elements on the physical and mechanical properties of a Cu-Fe-P-Cr alloy,” Materials Science and Engineering B: Solid-State Materials for Advanced Technology., Vol. 147, No. 1, pp. 1–6, (2008).
16. Wang, Y., Fu, H., Wang, J., Zhang, H., Li, W., and Xie, J., “Enhanced combination properties of Cu-0.8Cr alloy by Fe and P additions,” Journal of Nuclear Materials., Vol. 526, p. 151753, (2019).
17. Xu, S., Fu, H., Wang, Y., and Xie, J., “Effect of Ag addition on the microstructure and mechanical properties of Cu-Cr alloy,” Materials Science and Engineering A, Vol. 726, No. April, pp. 208–214, (2018).
18. Zhao, Z., Xiao, Z., Li, Z., Ma, M., and Dai, J., “Effect of magnesium on microstructure and properties of Cu-Cr alloy,” Journal of Alloys and Compounds., Vol. 752, pp. 191–197, (2018).
19. Zhang, P., Jie, J., Gao, Y., Li, H., Wang, T., and Li, T., “Influence of cold deformation and Ti element on the microstructure and properties of Cu-Cr system alloys,” Journal of Materials Research., Vol. 30, No. 13, pp. 2073–2080, (2015).
20. Fu, S. et al., “Effect of aging process on the microstructure and properties of Cu–Cr–Ti alloy,” Materials Science and Engineering A, Vol. 802, p. 140598, (2021).
21. Dong, Q., Shen, L., Cao, F., Jia, Y., Liao, K., and Wang, M., “Effect of Thermomechanical Processing on the Microstructure and Properties of a Cu-Fe-P Alloy,” Journal of Materials Engineering and Performance, Vol. 24, No. 4, pp. 1531–1539, (2015).
22. Jeong, E., Han, S., Goto, M., and Kim, S., “Effects of thermo-mechanical processing and trace amount of carbon addition on tensile properties of Cu-2.5Fe-0.1P alloys,” Materials Science and Engineering A, Vol. 520, No. 1–2, pp. 66–74, (2009).
23. Krishna, S. C., Gangwar, N. K., Jha, A. K., Pant, B., and George, K. M., “Enhanced strength in Cu-Ag-Zr alloy by combination of cold working and aging,” Journal of Materials Engineering and Performance, Vol. 23, No. 4, pp. 1458–1464, (2014).
24. Liu, Y., Li, Z., Jiang, Y., Zhang, Y., Zhou, Z., and Lei, Q., “The microstructure evolution and properties of a Cu-Cr-Ag alloy during thermal-mechanical treatment,” Journal of Materials Research, Vol. 32, No. 7, pp. 1324–1332, (2017).
25. Wang, K., Liu, K., and Zhang, J., “Microstructure and properties of aging Cu – Cr – Zr alloy,” Rare Metals, Vol. 33, No. 2, pp. 134–138, (2014).
26. Wen, H., Topping, T. D., Isheim, D., Seidman, D. N., and Lavernia, E. J., “Strengthening mechanisms in a high-strength bulk nanostructured Cu-Zn-Al alloy processed via cryomilling and spark plasma sintering,” Acta Materialia, Vol. 61, No. 8, pp. 2769–2782, (2013).
27. “Equilibrium Diagrams: Selected copper alloy diagrams illustrating the major types of phase transformation,” Copper Development Association, (1992).
28. Bauccio, M. L., ASM Metals Reference Book, 3rd Edition. ASM international, (1993).
29. Zeon, S., Choi, E., Hwan, S., Kim, S., Lee, J., and Field, B., “Progress in Materials Science Alloy design strategies to increase strength and its trade-offs together,” Progress in Materials Science, Vol. 117, No. August, p. 100720, (2021).
30. Olafsson, P. and Sandstro, R., “Calculations of electrical resistivity for Al - Cu and Al - Mg - Si alloys,” Materials Science and Technology, Vol. 17, No. 6, pp. 655–662, (2001).
31. Guinier, A., “Structure of age-hardened aluminium-copper alloys,” Nature, Vol. 142, pp. 569–570, (1938).
32. Preston, G. D., “Structure of age-hardened aluminium-copper alloys,” Nature, Vol. 142, pp. 570-571, (1938).
33. Monzen, R. and Watanabe, C., “Microstructure and mechanical properties of Cu-Ni-Si alloys,” Materials Science and Engineering A, Vol. 483–484, No. 1-2 C, pp. 117–119, (2008).
34. Zare, A. and Ekrami, A., “Effect of martensite volume fraction on work hardening behavior of triple phase (TP) steels,” Materials Science and Engineering A, Vol. 528, No. 13–14, pp. 4422–4426, (2011).
35. Guo, Z. and Li, L., “In fluences of alloying elements on warm deformation behavior of high-Mn TRIP steel with martensitic structure,” Materials & Design, Vol. 89, pp. 665–675, (2016).