Study On Sol-Gel Method Preparation And Properties Of Steel Based Ceramic Composite Coatings

In this paper,the research status of steel based ceramic composite coating and the research status of steel based ceramic composite coating prepared by sol-gel method are briefly reviewed and the technology of preparing steel based ceramic coating by sol-gel method is analyzed.The preparation and curing process of the steel based ceramic composite coating by sol-gel method were selected by using the test method combined with the change amount and the orthogonal test.The microstructure and cross-linking mechanism of the ceramic composite coating were studied by Scanning Electron Microscopy(SEM),Energy Dispersive X-ray Spectrometer(EDX)and X-ray Diffraction(XRD).The performance of steel-based ceramic composite coating was tested and analyzed,Based on the test results,the wear resistance,bonding strength,thermal shock resistance and corrosion resistance of the steel based ceramic composite coating was analyzed.Through several tests: it is feasible to prepare ceramic composite coating with excellent performance on the surface of Q235 steel substrate by sol-gel method.Ceramic composite coating formulation: the ratio of ceramic aggregate alumina,silica and chromium oxide is 4: 3: 1.The ratio of composite sol sodium silicate and silica sol is 7:3.the ratio of ceramic aggregate and composite sol is 1:1.2.Curing Process of Ceramic Composite Coating:the coating slurry was allowed to stand for 30 minutes,and stir per5 minutes fully.Curing method is that the beginning of temperature rise is 90 Degrees Celsius,insulation for 2 hours,rising temperature of 300 Degrees Celsius once again,insulation for an hour,increasing temperature to 400 Degrees Celsius,increasing 1-2Degrees Celsius per 1 minute,increasing temperature to 700 Degrees Celsius,the furnace cooling after insulation for 10 minutes.The composite coatings have Fe2Al4Si5018,NaAl(SiO3)2,Fe2SiO4,FeSi and Al86Cr14 by Scanning Electron Microscopy,Energy Dispersive X-ray Spectrometer and X-ray Diffraction.Ceramic composite coating surface quality and density is better,and Ceramic composite coating have less pores.Ceramic composite coating and Q235 steel substrate interface with chemical action,adsorption,mechanical action and diffusion,these effects complement each other,effectively improve the ceramic composite coating and steel substrate bonding strength.According to the performance test results of ceramic composite coating,Sol-gel method in the Q235 steel matrix ceramic composite coating than Q235 steel matrixwear resistance increased by 4.2 times.The average bonding strength of ceramic composite coating was 3.3MPa.The average bonding strength of ceramic composite coating is 0.85 MPa.The ceramic composite coating has a good bonding strength with the steel substrate.In 600 ?,700 ?,800 ?,900 ? thermal shock test,the number of thermal shocks of ceramic composite coating was 31 times,24 times,19 times,7times.The ceramic composite coating has good thermal shock resistance.Ceramic composite coating prepared by acid resistance,alkali resistance and salt resistance than Q235 steel were increased 8-9 times,6-7 times,3-4 times.Ceramic composite coating prepared by acid resistance,alkali resistance and salt resistance than1Cr18Ni9 stainless steel were increased 2-3 times,2-3 times,2 times.The ceramic composite coating can effectively improve the corrosion resistance of the substrate.