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采用溶胶-凝胶法在SUS 430合金表面制备Mn Co_2O_4尖晶石涂层,研究在固体氧化物燃料电池(SOFCs)阴极气氛下涂层对于SUS 430合金氧化动力学行为和电性能的效用.利用XRD,EDS和SEM对合金表面氧化物的相结构、表面和截面形貌以及成分进行表征,并采用四探针直流技术测量表面氧化物的面比电阻(ASR).结果表明,涂层合金在750℃空气中氧化1000 h形成2μm氧化物层,其主要由内层Mn-Cr尖晶石和外层掺杂的Mn-Co尖晶石构成;Cr_2O_3和Fe_2O_3的形成受到了抑制.氧化动力学曲线遵循抛物线规律,2段氧化速率常数分别为3.74×10~(-15)g~2/(cm4·s)(0~200 h)和7.06×10~(-15)g~2/(cm4·s)(200~1000 h),与无涂层SUS 430合金相比降低了1个数量级.在600~800℃范围内,氧化物层的ASR介于5.21~22.65 mΩ·cm~2范围内.Mn Co2O4涂层有效地增强了SUS 430合金的抗氧化能力和电性能.
The Mn Co 2 O 4 spinel coating was prepared on the surface of SUS 430 alloy by sol-gel method to study the effect of coating on the oxidation kinetics and electrical properties of SUS 430 alloy under the cathode atmosphere of solid oxide fuel cells (SOFCs) XRD, EDS and SEM were used to characterize the phase structure, surface and cross-section morphology and composition of the oxide on the alloy surface and the surface resistivity (ASR) of the surface oxide was measured by four-probe DC technique.The results showed that Oxidation in air at 750 ℃ for 1000 h resulted in the formation of 2μm oxide layer, which mainly consisted of the inner Mn-Cr spinel and the outer doped Mn-Co spinel. The formation of Cr 2 O 3 and Fe 2 O 3 was inhibited. Following the parabolic law, the oxidation rate constants of the second stage were 3.74 × 10 ~ (-15) g ~ 2 / cm 4 · s (0 ~ 200 h) and 7.06 × 10 ~ (-15) g ~ 2 / cm 4 · s (200-1000 h), which is one order of magnitude lower than that of the uncoated SUS 430 alloy.The ASR of the oxide layer ranges from 5.21 to 22.65 mΩ · cm ~ 2 in the range of 600 ~ 800 ℃. Mn Co2O4 coating effectively enhance the SUS 430 alloy oxidation resistance and electrical properties.