Corrosion resistance of aged die cast magnesium alloy AZ91D
Corrosion resistance of aged die cast magnesium alloy AZ91D
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DOI：
10.1016/j.msea.2003.08.060
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发表时间：
2004-02-05
期刊：
影响因子：
6.4
通讯作者：
StJohn, DH
中科院分区：
文献类型：
--
作者：
Song, GL;Bowles, AL;StJohn, DH
研究了压铸镁合金AZ91D在160℃时效后的腐蚀行为。合金的腐蚀速率在初始阶段随着时效时间的延长而降低，然后在时效时间大于45 h时再次增加。腐蚀速率对时效时间的依赖性可能与时效过程中微观结构和局部成分的变化有关。时效过程中，β 相 (Mg17Al12) 的析出仅沿着晶界发生。 β 相充当屏障，导致老化初始阶段的腐蚀速率降低。在后期，α晶粒中铝含量的减少使得α基体更加活跃，导致腐蚀速率增加。电化学测试结果还证实了α相和β相的变化对老化压铸AZ91D合金的耐腐蚀性的综合影响。 (C) 2003 Elsevier B.V. 保留所有权利。
The corrosion behaviour of die cast magnesium alloy AZ91D aged at 160degreesC was investigated. The corrosion rate of the alloy decreases with ageing time in the initial stages and then increases again at ageing times greater than 45 h. The dependence of the corrosion rate on ageing time can be related to the changes in microstructure and local composition during ageing. Precipitation of the beta phase (Mg17Al12) occurs exclusively along the grain boundaries during ageing. The beta phase acts as a barrier, resulting in a decreasing corrosion rate in the initial stages of ageing. In the later stages, the decreasing aluminium content of alpha grains makes the alpha matrix more active, causing an increase in the corrosion rate. Electrochemical testing results also confirm the combined effects of the changes in alpha and beta phases on the corrosion resistance of the aged die cast AZ91D alloy. (C) 2003 Elsevier B.V. All rights reserved.