The Preparation Process And Analysis On High Temperature Characteristics Of Co-Mn Composite Material

Solid Oxide Fuel Cell(SOFC) is a kind of new energy cell that high-temperature, high-efficiency and pollution-free, it has a broad prospect of application. Co-Mn spinel material has a wonderful property of anti-corrosion, it is well used in the interconnects of SOFC as a protection material. The preparation methods and the anti-corrosion property of Co-Mn spinel material are researched in this paper.Simple preparation by the raw materials of Co(NO3)3, Mn(NO3)2 and C2H3CoO2, C4H14MnO8 respectively, and the method of Sol-Gel that can polymerize Co3+ and Mn2+, drying and calcining the gel acquired by upper method to obtain the powder of Co-Mn spinel.Sample of electrode bar was made by the method of spark plasma sintering(SPS), powder of Co-Mn spinel and oxide of Cobalt and Manganese were used respectively as raw materials, we used Metallurgical Microscopy and Scanning Electron Microscope(SEM) to test its micro-structural, drainage method was adopted to test its density. Experimental results show that we can achieved a better sample when we use the powder of Co-Mn spinel as raw material and process parameters of sintering furnace on 1050?, 50 Mpa and 30 min.Preparation of Co-Mn coating adopted the advanced technique of High Energy Micro-arc Alloying(HEMMA), 304 stainless steel was used as matrix metal, Co-Mn alloy has the kind of Co-10 Mn and Co-40 Mn, Deposition of Co and Mn depends on its thermal flux, the higher value has the much droplet. In the technique of HEMMA, a reciprocity diffusion of elements is happening between the electrode rod and the base-metal(SUS304), thermal deformation in microscope is unavoidable, for decreasing the surface defects of coating, we deposited in a lower parameters after deposited in the regular parameters.Pre-oxidized temperature of Co-10 Mn coating and Co-40 Mn coating are 750? and 850? respectively, then we can achieved the Co-Mn spinel oxidation layer, for testing its anti-corrosion property in complex environments, we designed a high temperature condition of dry air in 800? for 100 h.The result of this high temperature corrosion experiment shows that Co-Mn alloy coating kept well after oxidized in complex conditions, and acted out a better adhesion to base-metal after oxidized; ASR value of sample oxidized for 100 h is considerably lower than the maximum requested value. EDS testing shows that all kinds of Co-Mn coating have the ability inhibiting the outward diffusion of Cr. A close coating of Cr2O3 formed between the outer oxidized layer and the inner base-metal.