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Microstructures and mechanical properties of AZ91 alloys prepared by multi-pass friction stir processing

  • Fang Chai (a1), Fei Yan (a1), Wei Wang (a1), Qichen Lu (a1) and Xiang Fang (a1)...

AZ91 magnesium plates with a thickness of 6 mm were subjected to one- and two-pass friction stir processing (FSP). Microstructures and mechanical properties of the experimental materials were investigated. The results show that FSP can significantly refine the microstructures of magnesium alloys, and two-pass FSP can prepare slightly finer grains in comparison with one-pass FSP. Some coarse β-Mg17Al12 phases existed in the first pass FSP break and dissolve into the matrix under the action of the second pass FSP. Microhardness distribution of the two-pass FSP AZ91 alloy exhibits no too much difference with that of the one-pass FSP AZ91 alloy. Due to further finer microstructures, the tensile properties of the two-pass FSP alloy are slightly higher than those of the one-pass FSP alloy. Both FSP AZ91 alloys show typical ductile fracture characteristics, while the dimples on the two-pass FSP specimen are much deeper and increase in quantity.

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1.Fooladi, S. and Kiahosseini, S.R.: Creation and investigation of chitin/HA double-layer coatings on AZ91 magnesium alloy by dipping method. J. Mater. Res. 32, 2532 (2017).
2.Mordike, B.L. and Ebert, T.: Magnesium properties applications potential. Mater. Sci. Eng., A 302, 37 (2001).
3.Shan, H., Zhang, Y., Li, Y., and Luo, Z.: Dissimilar joining of AZ31B magnesium alloy and pure copper via thermo-compensated resistance spot welding. J. Manuf. Process. 30, 570 (2017).
4.Feng, A.H. and Ma, Z.Y.: Enhanced mechanical properties of Mg–Al–Zn cast alloy via friction stir processing. Scripta Mater. 56, 397 (2007).
5.Bryla, K., Morgiel, J., Faryna, M., Edalati, K., and Horita, Z.: Effect of high-pressure torsion on grain refinement, strength enhancement and uniform ductility of EZ magnesium alloy. Mater. Lett. 212, 323 (2018).
6.Amani, S., Faraji, G., and Abrinia, K.: Microstructure and hardness inhomogeneity of fine-grained AM60 magnesium alloy subjected to cyclic expansion extrusion (CEE). J. Manuf. Process. 28, 197 (2017).
7.Zhao, S., Guo, E., Cao, G.J., Wang, L.P., Lun, Y.C., and Feng, Y.C.: Microstructure and mechanical properties of Mg–Nd–Zn–Zr alloy processed by integrated extrusion and equal channel angular pressing. J. Alloys Compd. 705, 118 (2017).
8.Schwarz, F., Eilers, C., and Krüger, L.: Mechanical properties of an AM20 magnesium alloy processed by accumulative roll-bonding. Mater. Charact. 105, 144 (2015).
9.Torbati-Sarraf, S.A. and Langdon, T.G.: Properties of a ZK60 magnesium alloy processed by high-pressure torsion. J. Alloys Compd. 613, 357 (2014).
10.Mishra, R.S. and Ma, Z.Y.: Friction stir welding and processing. Mater. Sci. Eng., R 50, 1 (2005).
11.Xie, S.Y., Li, R.D., Yuan, T.C., Chen, C., Zhou, K.C., Song, B., and Shi, Y.S.: Laser cladding assisted by friction stir processing for preparation of deformed crack-free Ni–Cr–Fe coating with nanostructure. Opt. Laser Technol. 99, 374 (2018).
12.Vijayavel, P. and Balasubramanian, V.: Effect of pin profile volume ratio on microstructure and tensile properties of friction stir processed aluminum based metal matrix composites. J. Alloys Compd. 729, 828 (2017).
13.Raja, A. and Pancholi, V.: Effect of friction stir processing on tensile and fracture behavior of AZ91 alloy. J. Mater. Process. Technol. 248, 8 (2017).
14.Arora, H.S., Grewal, H.S., Singh, H., Dhindaw, B.K., and Mukherjee, S.: Enhancing the mechanical properties of AE42 magnesium alloy through friction stir processing. Adv. Eng. Mater. 16, 571 (2014).
15.Liang, J.H., Li, H.J., Qi, L.H., Tian, W.L., Li, X.F., Chao, X.J., and Wei, J.F.: Fabrication and mechanical properties of CNTs/Mg composites prepared by combining friction stir processing and ultrasonic assisted extrusion. J. Alloys Compd. 728, 282 (2017).
16.Zhang, D.T., Wang, S.X., Qiu, C., and Zhang, W.: Superplastic tensile behavior of a fine-grained AZ91 magnesium alloy prepared by friction stir processing. Mater. Sci. Eng., A 556, 100 (2012).
17.Zhang, H.J., Liu, H.J., and Yu, L.: Microstructure and mechanical properties as a function of rotation speed in underwater friction stir welded aluminum alloy joints. Mater. Des. 32, 4402 (2011).
18.Mousavizade, S.M., Pouranvari, M., Ghaini, F.M., Fujii, H., and Chung, Y.D.: Laser-assisted friction stir processing of IN738LC nickel-based superalloy: Stir zone characteristics. Sci. Technol. Weld. Join. 21, 374 (2016).
19.El-Rayes, M.M. and El-Danaf, E.A.: The influence of multi-pass friction stir processing on the microstructural and mechanical properties of aluminum alloy 6082. J. Mater. Process. Technol. 212, 1157 (2012).
20.Chen, Y., Ding, H., Li, J., Cai, Z., Zhao, J., and Yang, W.: Influence of multi-pass friction stir processing on the microstructure and mechanical properties of Al-5083 alloy. Mater. Sci. Eng., A 650, 281 (2016).
21.Brown, R., Tang, W., and Reynolds, A.P.: Multi-pass friction stir welding in alloy 7050-T7451: Effects on weld response variables and on weld properties. Mater. Sci. Eng., A 513–514, 115 (2009).
22.Baruch, L.J., Raju, R., Balasubramanian, V., Rao, A.G., and Dinaharan, I.: Influence of multi-pass friction stir processing on microstructure and mechanical properties of die cast Al–7Si–3Cu aluminum alloy. Acta Metall. Sin. 29, 431 (2016).
23.Asadi, P., Faraji, G., and Besharati, M.K.: Producing of AZ91/SiC composite by friction stir processing (FSP). Int. J. Adv. Manuf. Technol. 51, 247 (2010).
24.Nakata, K., Kim, Y.G., Fuji, H., Tsumura, T., and Komazaki, T.: Improvement of mechanical properties of aluminum die casting alloy by multi-pass friction stir processing. Mater. Sci. Eng., A 437, 274 (2006).
25.Eftekhari, M., Movahedi, M., and Kokabi, A.H.: Microstructure, strength and wear behavior relationship in Al–Fe3O4 nanocomposite produced by multi-pass friction stir processing. J. Mater. Eng. Perform. 26, 3516 (2017).
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Journal of Materials Research
  • ISSN: 0884-2914
  • EISSN: 2044-5326
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