Effect of Heat Treatment on Microstructure Evolution and Mechanical Behavior of SKLB3 Alloy

Abstract:

In this paper, the effect of heat treatment on the microstructure and mechanical properties of hot forging Cu-Ni alloy was studied. Specimens of hot forged Cu-Ni alloy were subjected to first solution treated at 900^oC for 2hrs and then aged at different temperatures for 2hrs. The mechanical properties including tensile performance and impact energy, and the microstructure were measured for specimens before and after heat treatment. The results show that both solution and aging treatment have an influence on the grain growth. After heat treatment, the tensile strength decreases very slightly but the yield strength decreases seriously from 235.96MPa to 136.12MPa, while the elongation increases sharply from 36% to 48%. It was also observed that hardness values of the heat-treated alloys are all lower than that of the hot forged alloy. The measurement of Charpy impact energy with V-type notch was performed at 298K and 77K for different specimens. At both temperatures, the impact energies of the specimens are higher than 200J. The microstructure results show that at both temperatures, the alloys are fractured in a ductile mode.

• Periodical: Materials Science Forum (Volume 898)
• Pages: 380-386
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.898.380
• Online since: June 2017
• Authors: Wei Yuan*, Dong Mei Liu, Qiang Song Wang, Guo Liang Xie
• Keywords: Cu-Ni Alloy, Heat Treatment, Impact Energy, Mechanical Properties, Microstructure Evolution

References

[1] J. Zhang, Q. Wang, Y. Wang, et al. Revelation of solid solubility limit Fe/Ni = 1/12 in corrosion resistant Cu-Ni alloys and relevant cluster model. Journal of Materials Research, 25(2010)328-336.

DOI: 10.1557/jmr.2010.0041

[2] N. Liu, L. Zhou, L. Ling, et al. Processing map and hot deformation mechanism of novel nickel-free white copper alloy. Transactions of Nonferrous Metals Society of China, 24(2014)3492-3499.

DOI: 10.1016/s1003-6326(14)63493-2

[3] S. Cincera, S. Barella, M. Bellogini, et al. De-nickelification of 70/30 Cupronickel Tubing in a Cooling Heat Exchanger. Journal of Failure Analysis & Prevention, 12(2012)300-304.

DOI: 10.1007/s11668-012-9565-1

[4] F.J. Ansuini, F.A. Badia. High strength micro duplex Cu-Ni-Zn alloys. Metallurgical & Materials Transactions B, 4(1972)15-20.

DOI: 10.1007/bf02649599

[5] V. Stolyarov, R.Z. Valiev R, Y.T. Zhu. Enhanced low-temperature impact toughness of nanostructured Ti. Applied Physics Letters, 88(2006)041905-041905-3.

DOI: 10.1063/1.2167800

[6] Y. Tomota, Y. Xia, K. Inoue. Mechanism of low temperature brittle fracture in high nitrogen bearing austenitic steels. Acta Materialia, 46(1998)1577-1587.

DOI: 10.1016/s1359-6454(97)00350-9

[7] K. Han, V.J. Toplosky, R. Goddard, et al. Impacts of Heat Treatment on Properties and Microstructure of Cu16at%Ag Conductors. IEEE Transactions on Applied Superconductivity, 22(2012)6900204-6900204.

DOI: 10.1109/tasc.2011.2174575

[8] Q. Miao, L.X. Hu, X. Wang, E.D. Wang, Grain growth kinetics of a fine-grained AZ31 magnesium alloy produced by hot rolling, J. Alloys Compd. 493 (2010) 87-90.

DOI: 10.1016/j.jallcom.2009.12.049

[9] A. Loucif, R.B. Figueiredo, T. Baudin, F. Brisset, R. Chemam, T.G. Langdon, Ultrafine grains and the Hall-Petch relationship in an Al-Mg-Si alloy processed by high-pressure torsion, Mater. Sci. Eng. A 532 (2012) 139-145.

DOI: 10.1016/j.msea.2011.10.074

[10] P. Lehto, H. Remes, T. Saukkonen, H. Hänninen, J. Romanoff, Influence of grain size distribution on the Hall-Petch relationship of welded structural steel, Mater. Sci. Eng. A 592 (2014) 28-39.

DOI: 10.1016/j.msea.2013.10.094

[11] C.H. Gür, I. Yildiz. Utilization of Non-destructive Methods for Determining the Effect of Age-Hardening on Impact Toughness of 2024 Al–Cu–Mg Alloy. Journal of Nondestructive Evaluation, 27(2008)99-104.

DOI: 10.1007/s10921-008-0028-2

[12] O. Elsebaie, A.M. Samuel, F.H. Samuel, et al. Impact toughness of Al–Si–Cu–Mg–Fe cast alloys: Effects of minor additives and aging conditions. Materials & Design, 60(2014)496-509.

DOI: 10.1016/j.matdes.2014.04.031