| Solid oxide fuel cell (SOFC) is regarded as a very potential power energy in the future due to high efficiency, high waste-heat utilization and low emission of pollutants. The connecting body is a very important component in a SOFC stack,which is used to collector current,connect anode and cathode of adjacent single cells in stack, distribute gas and barrier fuel and air. With the development of anode supported SOFC and the thim film of electrolyte,the working temperature of SOFC gradually decreased..It is possible to use low cost alloy material as the SOFC connector material.SUS430is one of the most representative of the candidate materials in many of the alloy material.However,lack of high temperature oxidation resistance and cathode poisoning producted of Cr volatile severely limits its application in SOFC. So far, the metal interconnect is still a bottleneck problem to urgent need to overcome the in SOFC technology.Tt is an effective way to solve the problem to coverage coating on the surface of the alloy.In this paper,the Lao.8Sro.2Mn03oxidation resistant coating on SUS430alloy was prepared by Sol-Gel method.The preparation process of alloy coating were studied.It is good for the wettability of the alloy and the coating of the coating to grind the surface of the specimen with abrasive paper and fine sandpape and then dip into the citric acid throngh the comparative study of different treatment methods of alloy. It is found that MRCM was1.5in favor of coating preparation through the study of the molar ratio of citric acid and metal ions (MRCM).Through the experimental of the effect of dipping time on porosity of coating,it was found that the porosity of coating was significantly reduced with the increase of the dipping time. The porosity of LSM coating was reduced by56%after6times of impregnation.Through the analysis of different firing system under the coating morphology, which was in the protection of gas at850℃calcination has good surface topography with relatively uniform size particles, clear outline, no obvious pores, relative density and about41.16μm thickness.The performance of LSM alloy coating was researched in this paper. Alloy coating sintered at850℃, did not change significantly at850℃after10h oxidation under the observation of the microstructure of coating after oxidation for10h. The coating surface was still smooth and dense, only a small amount of oxide particles.It showed that the coating had good protection performance, and reduced the oxidation rate of the alloy.The phase of the coating did not change significantly,and was still LSM phase and matrix phase after100h oxidation through the XRD of alloy coating sintered at850℃in N2 before and after oxidation.The temperature oxidation resistance of SUS430alloy coating was significantly improved through the research of oxidation kinetics. The antioxidant properties of coating alloy sintered at850℃was best,and the oxidation rate constant was9.8×10-15g2/(cm4.s).The area specific resistance of alloy sintered at850℃in N2measured in area after500h oxidation was about3.08mΩ·cm2through the study of the conductive properties of the alloy. We can calculate that the ASR was3.08mΩ·cm2after4×104h oxidation.It meet the demand of SOFC on conductive connector. |
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