Ni-Al系金属间化合物熔盐热腐蚀后的交流阻抗研究

AC IMPEDANCE OF Ni-AI INTERMETALLIC COMPOUNDS AFTER HOT CORROSION

近年来,Ni-Al基金属间化合物的研究特别活跃,是一类潜在高温结构材料。作者曾研究了铁基合金熔盐腐蚀的阻抗特征,提出了阻抗模型及图谱解析方法。本文研究Ni-Al系金属间化合物熔盐热腐蚀的阻抗特征。 材料为Ni3Al和NiAl（Fe）金属间化合物。X-衍射分析证明是此结构。Ni3Al成分为（at%）:Al 21.2,B 0.1,Zr 0.3,Ni余量;NiAl（Fe）成分为（at%）:Al 19.68,Fe 15.03,Mo 2.0,Hf 0.27,

Hot corrosion of Ni-Al intermetallic compounds in molten (Na,K, Li)_2SO_4 has been studied by AC impedance technique. The hot corrosion of Ni-Al alloys was shown to be a diffusion-controlled process.The parameters in the corresponding equivalent circuit was calculated by the IFP technique. The results showed that the value of the charge-transfer resistance of Ni-Al alloys was very small,which indicates the lower anticorrosive character of the alloys. The mechanism of Ni-Al alloys during hot corrosion has been discussed.