Research On Precursor Conversion Of SiOC(Fe) Ceramics Based On DLP Technology

Ceramic materials have excellent mechanical properties,high temperature resistance and corrosion resistance.Now ceramic materials play an important role in more and more high-precision fields.Due to the high hardness,high brittleness and low fracture toughness of ceramics,ceramic materials are subject to many restrictions during processing.Traditional molding process has been difficult to meet the processing of ceramic parts with complex shapes or micro-nano structures.Three-dimensional printing technology has attracted widespread attention as an emerging molding manufacturing technology.This technology has great potential in the field of molding manufacturing of high-performance ceramics.Three-dimensional printing is expected to break through the technical bottleneck of traditional ceramic processing and production and expand the application range of functional ceramics The manufacturing technology of high-performance ceramic materials provides a transformative driving force.In this paper,we combined the precursor conversion SiOC（Fe）ceramic technology with 3D printing technology,synthesize a low-viscosity,high-sensitivity and good curing strength iron compound modified precursor photosensitive resin,which can be formed complex structure by digital light processing technology（DLP）.Various complex structures and micro-nano features.Pyrolysis in 1000℃argon atmosphere can obtain a ceramic product model with complete shape and uniform shrinkage.The phase transition and volume shrinkage of ceramic products during ceramicization have been studied,laying a foundation for the application of precursor conversion SiOC（Fe）ceramics by DLP basis.Here are the main findings:1.Synthetic vinyl ferrocene-modified precursor resin:TMPTA mass fraction is 30%,photoinitiator 819 mass fraction is 1%,vinyl ferrocene mass fraction is 6%,the precursor resin has good molding performance,the transmission depth of the precursor photosensitive resin at this time is 127.99μm,and the critical exposure value is 2340.65 mj/cm².Through DLP printing technology,the prepared precursor resin can be molded into various structures,and a suitable cracking system can be formulated in an argon atmosphere to obtain a ceramic model with complete structure and good surface morphology.The modified precursors were cracked under different temperature conditions.The results showed that as the cracking temperature increased,the amorphous carbon in the cracked product gradually transformed into an ordered structure,and crystalline Fe₃Si is precipitated in the ceramic product;the cracking temperature rises,the hardness of the ceramic product obtained by cracking gradually increases,the hardness of the ceramic product after cracking at 1000℃is 5.92GPa;the mass of the ceramic model remains at the cracking temperature of 1000℃is 45.27%and the density is 1.89g/cm³,and the linear shrinkage is 32.94%.2.The preparation of ceramic precursor photosensitive resin modified with iron acetylacetonate,with the increase of the amount of iron acetylacetonate doped,the exposure energy required for every 50um cured layer thickness is increased from 0.5wt.%256.2mj/cm²to 3wt.%of 717.85mj/cm².The phase changes of the ceramic products of the precursor resin modified with iron acetylacetonate were studied,the results showed that:the absorption peak height at 23°in the XRD pattern increased with the increase of the amount of iron acetylacetonate,and the half-peak width decreased.After cracking,the ordered structure in the ceramic product increases.The structure of the ceramic model was complete at 1000℃,the linear shrinkage of the ceramic model was 43.2%,the mass loss was 54.6%,the bulk density was 1.804g/cm³,and the hardness value was 8.16GPa.