The microstructure, oxidation behaviour and oxide film morphology of AZ31, AZ31–0.5Ca, AZ31–0.5Y and AZ31–0.5Ca-0.5Y alloys were investigated. The results demonstrate that the oxidation behaviour of all the experimental alloys can be divided into two distinct parts: the incubation zone, which follows a parabolic law, and the non-protective oxidation zone. The resistance to high-temperature oxidation of AZ31 was enhanced by the incorporation of Ca or Y. The outcomes demonstrated that the oxidation behaviour of AZ31 was highly commendable. The observation of the micro-morphology by scanning electron microscopy (SEM) revealed that the presence of calcium (Ca) and yttrium (Y) can reduce the amount and change the shape of the low-melting-point phase of magnesium (Mg) and aluminium (Al) (MgAl). The morphology and composition of the oxide films were analysed, and it was found that the AZ31–0.5Ca and AZ31–0.5Ca-0.5Y oxides are thinner and more dense, and that the failure is in the form of peeling and detachment. Furthermore, it was observed that the oxides of AZ31 and AZ31–0.5Y become loose and porous at high temperatures. The antioxidant capacity of calcium is enhanced by increasing the film density, while yttrium enhances the resistance to high-temperature oxidation by depleting the low-melting phase and changing the nature of α-Mg. The simultaneous addition of Ca and Y results in cracking and peeling of the film layer.

中文翻译：

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Ca、Y微合金化对AZ31高温氧化行为的影响


研究了AZ31、AZ31–0.5Ca、AZ31–0.5Y和AZ31–0.5Ca-0.5Y合金的显微组织、氧化行为和氧化膜形貌。结果表明，所有实验合金的氧化行为都可以分为两个不同的部分：遵循抛物线定律的孕育区和非保护性氧化区。 Ca或Y的掺入增强了AZ31的抗高温氧化能力。结果表明AZ31的氧化行为非常值得称赞。通过扫描电子显微镜（SEM）对微观形貌的观察表明，钙（Ca）和钇（Y）的存在可以减少镁（Mg）和钇（Y）的低熔点相的量并改变其形状。铝（Al）（MgAl）。对氧化膜的形貌和成分进行分析，发现AZ31-0.5Ca和AZ31-0.5Ca-0.5Y氧化物膜层较薄且致密，失效形式为剥离和脱落。此外，还观察到 AZ31 和 AZ31-0.5Y 的氧化物在高温下变得松散且多孔。钙通过增加膜密度来增强抗氧化能力，而钇通过耗尽低熔相和改变α-Mg的性质来增强抗高温氧化能力。同时添加Ca和Y会导致膜层破裂和剥落。