Improving corrosion resistance of RE-containing magnesium alloy ZE41A through ECAP
来源期刊：Journal of Rare Earths2009年第5期
论文作者：江静华 马爱斌 SAITO Naobumi 沈志欣 宋丹 卢富敏 Yoshinori NISHIDA 杨东辉 林萍华
文章页码：848 - 852
摘 要：Significant grain refinement was achieved in rare earth （RE） containing aeronautic magnesium alloy ZE41A through equal-channel angular pressing （ECAP） using rotary die at 603 K. Influence of ECAP pass number on its microstructure change and corrosion behavior was investigated by optical microscope （OM）/scanning electron microscope （SEM） observation and potentiostatic polarization tests in aqueous solution of NaCl, respectively. The results showed that ultrafine equiaxial grains （about 2.5 μm） were obtained over 16 passes due to plastic-induced grain refinement accommodated by dynamic recrystallization. The lower corrosion current density and nobler corrosion potential correlated with large number of pressing passes were attributed to the low tendency toward localized corrosion with broken secondary phase after homogenization on ultrafine-grained Mg matrix. The multi-pass ECAP method made the ZE41A aeronautic magnesium alloy more attractive since severe plastic deformation may significantly improve its corrosion resistance besides superior mechanical properties.
江静华1,2，马爱斌1，SAITO Naobumi3，沈志欣1，宋丹1，卢富敏1，Yoshinori NISHIDA3，杨东辉1，林萍华1
1. College of Materials Science and Engineering,Hohai University2. Department of Materials Science and Engineering,North Carolina State University3. National Institute of Advanced Industrial Science and Technology
摘 要：Significant grain refinement was achieved in rare earth （RE） containing aeronautic magnesium alloy ZE41A through equal-channel angular pressing （ECAP） using rotary die at 603 K. Influence of ECAP pass number on its microstructure change and corrosion behavior was investigated by optical microscope （OM）/scanning electron microscope （SEM） observation and potentiostatic polarization tests in aqueous solution of NaCl, respectively. The results showed that ultrafine equiaxial grains （about 2.5 μm） were obtained over 16 passes due to plastic-induced grain refinement accommodated by dynamic recrystallization. The lower corrosion current density and nobler corrosion potential correlated with large number of pressing passes were attributed to the low tendency toward localized corrosion with broken secondary phase after homogenization on ultrafine-grained Mg matrix. The multi-pass ECAP method made the ZE41A aeronautic magnesium alloy more attractive since severe plastic deformation may significantly improve its corrosion resistance besides superior mechanical properties.
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