铈镧混合稀土对AM60镁合金耐蚀耐磨性能的影响(英文)

Effects of Lanthanum and Cerium Mixed Rare Earth Metal on Abrasion and Corrosion Resistance of AM60 Magnesium Alloy

模板通过析氢集气法、增重法、电化学测试和摩擦磨损性能测试等方法,研究了添加铈镧混合稀土对AM60镁合金耐蚀、耐磨性能的影响。结果表明,在0.35%Na Cl溶液中加入铈镧混合稀土后的AM60镁合金析氢腐蚀电流密度下降、腐蚀电位升高,极化电流密度降低,极化电阻增大、容抗减小,改善了腐蚀电化学性能。其原因归结于混合稀土加入后,细化了镁合金的α相和Mg17Al12相,合金形成的Al2Ce和Al11La3新相抑制了阴极去极化的历程、合金表面形成的Ce O2、La2O3复合阳极氧化膜阻滞了合金的溶解,提高了耐蚀性。加入铈镧混合稀土后,AM60镁合金的摩擦系数较AM60合金明显降低,比磨损率减小,改善了合金的摩擦磨损性能,在0.35%Na Cl溶液中低载荷、滑动速度和短距离滑动时AM60镁合金的主要磨损形式为氧化磨损。

The effects of lanthanum and cerium mixed rare earth metal on the abrasion and corrosion resistance of AM60 magnesium alloy were analyzed by the hydrogen evolution method, mass gain test, electrochemical test, as well as friction and wear characteristics test. It can be found that after adding lanthanum and cerium mixed rare earth metal, AM60 magnesium alloy＇s electrochemical properties, friction and wear performance are all improved in 0.35%NaC l solution. For example, hydrogen evolution corrosion current density, polarization current density and capacitance all decrease while its corrosion potential and polarization resistance increase. Moreover, its friction coefficient and specific wear rate decrease. This is because adding of lanthanum and cerium results in refining of the grains of phase and Mg17Al12 phase of AM60 magnesium alloy and forming of new Al2 Ce and Al11La3 phases, which inhibit the progress of cathodic depolarization, whilst the added Ce and La form a composite anodic film on the surface of the alloy, which block the dissolution and improve the corrosion resistance.