ABSTRACT

The effects of Ga addition (1, 2, 3 and 5 wt-%) on the corrosion behaviour of high strain rate rolled Mg–Ga alloys are firstly investigated by weight loss measurement and electrochemical testing. Solute Ga atoms can reduce the corrosion potential but improve the corrosion resistance of the alloy with the Ga content lower than 3 wt-%. The Mg–3Ga alloy sheet is the most corrosion-resistant with the weight loss rate of 0.52 mg cm⁻² day⁻¹ for 7 days immersion in 3.5% NaCl solution. The corrosion resistance improvement can be ascribed to the enhanced compactness of the corrosion film associated with Ga addition. The Ga addition affects the DRX degree, but the DRX degree is not the crucial factor in the corrosion of the alloys. The Mg₅Ga₂ dynamic precipitates are detrimental to the corrosion resistance of the Mg–Ga alloys and play a relatively important role in the corrosion of the Mg–5Ga alloy.

摘要

首先通过失重测量和电化学测试研究了 Ga 添加量（1、2、3 和 5 wt%）对高应变率轧制 Mg-Ga 合金腐蚀行为的影响。当Ga含量低于3wt-%时，溶质Ga原子可以降低腐蚀电位，但可以提高合金的耐腐蚀性能。Mg-3Ga 合金板是最耐腐蚀的，在 3.5% NaCl 溶液中浸泡 7 天，重量损失率为 0.52 mg cm ^-2  day ^-1。耐腐蚀性的提高可归因于与 Ga 相关的腐蚀膜致密性的增强。Ga的添加会影响DRX度，但DRX度不是合金腐蚀的关键因素。Mg ₅ Ga ₂ 动态析出物对 Mg-Ga 合金的耐腐蚀性是不利的，并且在 Mg-5Ga 合金的腐蚀中起相对重要的作用。