MnCl_2对镁合金废旧料组织性能的影响

Effect of MnCl_2 on the Structure and Properties of Magnesium Alloy Wastes

利用等离子发射光谱仪、金相分析、电镜、万能电子材料试验机、腐蚀试验等方法研究了含有不同量的MnCl2熔剂对镁合金废旧料的力学性能、组织、断口形貌以及腐蚀行为的影响。研究表明,MnCl2可以降低镁合金废旧料中的Fe含量,同时会增加镁合金的Mn量,使用含MnCl2的熔剂可将镁废旧料中的Fe含量降到0 0072%以下。采用含MnCl2的熔剂可以提高试样的σb和δ。当合金中的Mn量超过一定程度后,对镁合金的力学性能会产生不利的影响。金相观察表明,净化处理对断口形貌无明显的影响,不改变AZ91镁合金的断裂机理,断口均成准解理断裂。腐蚀试验表明,采用含30%MnCl2的熔剂可以使试样的腐蚀速率从20 9mg/(cm2·d)降到6 4mg/(cm2·d)。

The effects of the fluxes containing MnCl_2 on the mechanical properties, structure, fracture pattern and corrosion behavior of magnesium alloy wastes have been studied by ICP spectroscopy, metallographic analysis, SEM, material testing machine and corrosion test. It is discovered that MnCl_2 can decrease the Fe content of magnesium alloy wastes. At the same time, the Mn content in the melt will increase. The Fe content of magnesium alloy wastes can be decreased to below 0.0072% by the flux containing MnCl_2. The results show that theσ_b and δ can be improved by the fluxes containing MnCl_2. But excessive Mn content will have deleterious effect on the mechanical properties of magnesium alloy. The metallographic analysis results show that the purification treatment has not obvious effect on metallurgical structure. The fracture mechanism of AZ91 has not been changed, and the fractures are still quasi-cleavage crack. The corrosion test results show that the corrosion rate of Mg alloy can be decreased from 20.9mg/(cm2·d) to 6.4 mg/(cm2·d) by the flux containing 30% MnCl_2.