Microstructure and corrosion behaviour of Mg-2Gd-1Y-1Zn-0.2Zr (at-%) alloy processed by equal channel angular pressing

作者：Jiang, J.; Yin, L.; Lu, F.; Ma, A.^*; Song, D.; Zhang, L.; Yang, D.; Chen, J.

来源：Corrosion Engineering, Science and Technology, 2014, 49(4): 316-320.

DOI：10.1179/1743278214Y.0000000152

• Mg alloy
• Equal channel angular pressing (ECAP)
• Corrosion resistance
• Grain refinement

Significant grain refinement was achieved in a new Mg-2Gd-1Y-1Zn-0.2Zr (at-%) alloy through multipass equal channel angular pressing (ECAP) at 623 K. Corrosion behaviours of the ECAPed alloy were investigated by hydrogen evolution and electrochemical measurement in NaCl solution at room temperature. The results showed that a large number of intergranular phases were stretched and gradually broken above four ECAP passes, but the fine grained alpha-Mg phase was much easier to grow after 12 ECAP passes for dynamic recrystallisation. The corrosion resistance of the ECAPed Mg alloy in a fine grained state considerably increases, compared with that in the as cast state. After four ECAP passes, the corrosion potential, the pitting potential and the resistance value achieved -1.55 V, -1.39 V and 2.08 K Omega respectively. However, excessive ECAP passes reduced the corrosion resistance of the fine grained Mg alloy, due to grain coarsening and the gradual loss of barrier effect of intergranular phases.

• 出版日期2014-6
• 单位河海大学; 南京理工大学