镁合金在多因素耦合作用下的腐蚀行为

Corrosion Behavior of Magnesium Alloys under the Multi-Factor Coupling Effects

摘要:

选择铸态和挤压态AZ61镁合金，采用SEM、XRD和电化学测试等分析手段，研究在120 ℃和1.8 MPa的NaCl气氛中镁合金的腐蚀形貌和腐蚀机理。结果表明，在NaCl气氛、温度、压力和合金组织状态等多因素耦合作用下，由于β相重新分布以及晶粒尺寸变小，使得挤压态AZ61镁合金的腐蚀速率大于铸态的腐蚀速率，但腐蚀产物均以Mg(OH)2为主。较高的温度与NaCl气氛共同作用是加快镁合金腐蚀的主要原因

Abstract:

The cast AZ61 magnesium alloy and the extruded alloy were chosen to study the corrosion morphology and mechanism by means of SEM, XRD and electrochemical testing, under the NaCl atmosphere at 120 oC and 1.8 MPa. The results show that due to the multi-factor coupling effects of NaCl atmosphere, temperature, pressure and microstructure, the corrosion rate of the extruded AZ61 magnesium alloy is larger than that of the cast AZ61 alloy, because of the re-distribution of β phases and smaller grain size. But both of the corrosion products are mainly Mg(OH)2. The environmental factors play an important role in the corrosion behavior of magnesium alloys. Higher temperature and sodium chloride atmosphere work together to accelerate the corrosion rate of Mg alloys