Liu Xiaoda, Yin Ming, Zhang Shaohua, Wei Huan, Liu Baosheng, Du Huayun, Hou Lifeng, Wei Yinghui
College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
College of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China.
Materials (Basel). 2018 Sep 24;11(10):1812. doi: 10.3390/ma11101812.
The corrosion behavior of Mg-3Al-Ge ( = 1, 3, 5) alloy in as-cast and as-solid was investigated by virtue of microstructure, corrosion morphology observation, and electrochemical measurement. Among the as-cast alloys, the corrosion rate of Mg-3Al-1Ge with a discontinuous bar-morphology was the highest, which was 101.7 mm·a; the corrosion rate of Mg-3Al-3Ge with a continuous network distribution was the lowest, which was 23.1 mm·a; and the corrosion rate of Mg-3Al-5Ge of Ge-enriched phase with sporadic distribution was in-between, which was 63.9 mm·a. It is suggested that the morphology of the Mg₂Ge phase changes with a change in Ge content, which affects the corrosion performance of the alloy. After solid solution treatment, the corrosion rate of the corresponding solid solution alloy increased-Mg-3Al-1Ge to 140.5 mm·a, Mg-3Al-3Ge to 52.9 mm·a, and Mg-3Al-5Ge to 87.3 mm·a, respectively. After investigation of the microstructure, it can be suggested that solid solution treatment dissolves the MgAl phase, which changes the phase composition of the alloy and also affects its microstructure, thus affecting its corrosion performance.
通过微观结构、腐蚀形貌观察和电化学测量，研究了Mg-3Al-Ge（=1、3、5）合金在铸态和凝固态下的腐蚀行为。在铸态合金中，具有不连续棒状形态的Mg-3Al-1Ge的腐蚀速率最高，为101.7 mm·a⁻¹；具有连续网络分布的Mg-3Al-3Ge的腐蚀速率最低，为23.1 mm·a⁻¹；具有零星分布的富Ge相的Mg-3Al-5Ge的腐蚀速率介于两者之间，为63.9 mm·a⁻¹。结果表明，Mg₂Ge相的形态随Ge含量的变化而变化，这影响了合金的腐蚀性能。固溶处理后，相应固溶合金的腐蚀速率分别增加——Mg-3Al-1Ge增加到140.5 mm·a⁻¹，Mg-3Al-3Ge增加到52.9 mm·a⁻¹，Mg-3Al-5Ge增加到87.3 mm·a⁻¹。通过对微观结构的研究，可以认为固溶处理溶解了MgAl相，这改变了合金的相组成，也影响了其微观结构，从而影响了其腐蚀性能。
