Mechanism Study Of Multiple Physical Fields In Preparation Of Abosorbing Films Based On Tape Casting Process

With the extensive application of electromagnetic wave technology,the negative impacts emerge gradually when it serves humanity.Therefore,the industry of absorbing materials draws worldwide attention.The research is based on the tape casting process,which is used to fabricate the absorbing thin film.The study focuses on the foundation of the tape casting process and explores how the characteristics of slurry and the process parameters influence the thickness and the degree of cure of the film.The research builds a muti-physical field model to describe tape casting process by both experiments and simulation analysis.The main contents of the research are tape casting blade coating rheodynamics model and drying process model of thin films in tape casting.The first conclusion includes establishing the fluid dynamics numerical calculation model,and numerically explaining how the rheological properties of the fluid constitutive relation and fluid parameters such as plate velocity,blade gap,initial static pressure take effect on the thickness of the thin films.This part of the study shows that the rheological properties of the film slurry and process parameters can be obtained before the film material is fabricated by the tape casting method,and the numerical calculation model can be used to accurately predict the film thickness.The second conclusion includes establishing numerical calculation model of tape casting drying process,and exploring how the temperature of dry atmosphere,the temperature distribution and the properties of slurrry influence the velocity field,the temperature feild,the solvent vapor concentration field and the residual content of solvent in the thin film.Based on the research of tape casting drying model,the cure kinetics theory is adoped to investigate the mechanism of degree of cure in the thin film.In this part of the study,the modified formula of solvent evaporation characteristics in the slurry was innovatively proposed,and then the calculation method of the critical transition point of evaporation rate was proposed.Then,the solvent vapor concentration field in the drying process of the slurry was calculated using the Guess-Correction iterative process,and finally the change of film thickness in the drying process was calculated.In addition,according to the solution of multi-physical fields,the curing degree of the film was obtained by taking the soluting into the cure dynamic relationship of the adhesive.This research is based on the multiple basic subject cross effects in tape casting process when fabricate the thin film,establishes the multiphsical analysis model and achieves the numerical calculation to study qualitatively and quantitatively relationship of how the slurry properties and the process parameters influence the macroscopic,microstructure and degree of cure of the thin film.