Effect of Annealing and Aging Treatment on Pitting Corrosion Resistance of Fine-Grained Mg-8%Al-0.5%Zn Alloy
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In order to study the influence of plastic deformation, annealing and aging treatment on pitting corrosion, the AZ80Mg alloy was subjected to equal-channel angular pressing (ECAP) by route R at 325°C for up to 4 ECAP passes (P) and annealing conditions of 523 K, 623 K and 723 K followed by aging treatment at 6 h and 12 h. A microhardness and corrosion study was accomplished and microstructural evolution was recorded using optical microscopy (OM), scanning electron microscopy and electron backscatter diffraction (EBSD). OM and EBSD analysis showed that a fine-grain microstructure with average grain sizes of 32.87 µm and 6.35 µm was achieved after 2P and 4P of ECAP, respectively. During annealing and aging treatment, the fine-grain Mg alloy revealed that the maximum microhardness and improved corrosion resistance were observed mainly due to redistribution of β-secondary phases. Specifically, 12 h aged specimens at 523 K represented maximum microhardnesses of about 85 Hv and 87 Hv for ECAP-2P and -4P, respectively. Also, 12 h aging at 723 K appeared preferable for accomplishing enhanced corrosion properties.
This work was supported by DRDO-NRB, Government of India, under Grant Number NRB/4003/PG/366.
- 3.G.M. Naik, S. Narendranath, and S.S. Satheesh Kumar, J. Met. Mater. Miner. 29, 2 (2019).Google Scholar
- 28.C. Zhang, J. Liu, and B. Chen, Appl. Phys. A 125, 2 (2019).Google Scholar
- 29.C. Zhang, J. Liu, and B. Chen, Ceram. Int. 44, 16 (2018).Google Scholar
- 35.G.M. Naik, G.D. Gote, S. Narendranath, and S.S. Satheesh Kumar, Adv. Mater. Res. 7, 2 (2018).Google Scholar