Ca和Ce对阻燃镁合金组织和性能的影响

Effect of Ce and Ca Additions on Property and Structure of Ignition-Proof Magnesium Alloy

镁合金在熔炼过程中容易产生氧化燃烧,因此必须采取有效的措施对其加以保护,合金化是一种理想的阻燃方法。研究了添加不同Ce含量对Mg-Ca合金的阻燃性能、耐腐蚀性能以及力学性能的相关影响。结果表明:随着Ce含量的增加,使Mg-Ca合金的燃点大幅度提高;当Ce含量提高到1.2%时,镁合金的燃点达到780℃;Ce元素的添加使镁合金的晶粒细化,产生固溶强化和析出强化现象,镁合金的力学性能有明显提高。Ce元素与Mg形成金属间化合物Mg17Ce2,一方面致密的Mg17Ce2抑制腐蚀的进行,另一方面Mg17Ce2与基体Mg形成局部点偶腐蚀;当Ce含量为1.2%时,耐腐蚀性最好。

The melting of magnesium alloys is prone to oxidation and even burning, therefore effective measures must be taken to protect it, alloying is a perfect method to prevent burning. The ignition-proof, corrosion resistance and mechanical property of Mg-1.2Ca alloy with different Ce additions were studied. The result shows that with the content of Ce increasing, the ignition points of Mg-1.2Ca increased significantly. When the content of Ce reached 1.2%, the ignition point ofMg-1.2Ca-1.2Ce alloy reached 780℃. The addition of Ce element makes the grain of magnesium alloys more refined, which leads to solid solution strengthening and precipitation strengthening. The mechanical property of the alloy increases obviously. Ce and Mg forms intermetallic compound Mg17Ce2, on one hand the dense Mg17Ce2 inhabits corrosion; on the other hand Mg17Ce2 and matrix Mg form partly galvanic corrosion. When Ce content was 1.2%, the corrosion resistance is the best.