Research On The Key Technology Of Photocatalytic-roll-vibratied Complex Polishing For Diffidult-to-Process Materials

Difficult-to-process materials are widely used in areas of aerospace,advanced weapons,ultra-remote communications,photovoltaic power generation,rail trains,and consumer electronics.The key manufacturing technologies of difficult-to-process materials have been becoming an important guarantee for China’s long-term social stability and people’s wonderful lives.At present,the trend of anti-globalization is increasingly intensified,and some western countries will restrict China’s manufacturing technology of difficult-to-process materials as an important mean to engage in unilateralism and protectionism.Building up a new development pattern and promoting the supply-side reform of ultra-precision hard-to-process materials,requires us to practice internal skills,strong and weak items,and make up short board.To rich the polishing technology of difficult-to-process materials(such as silicon carbide,gallium nitride,diamond),the photocatalytic assisted chemical polishing technology and non-resonant vibratied assisted physical polishing technology are integrated,a new method for photocatalytic-roll-vibratied complex polishing is proposed,the photocatalytic-roll-vibratied complex polishing device is builded.Take silicon carbide,a typical difficult-to-process material,as an example,the oxidation and removal characteristics of photocatalytic-roll-vibratied complex polishing are studied.The main contents are included:(1)Design of the asymmetric vibration-assisted stage.Based on the theory of flexible mechanism,a new asymmetric vibration-assisted stage is designed.The stage is characterized by asymmetric displacement and asymmetric stiffness,and can effectively remove the single-directional surface textures generated by roll-type polishing processs,and realizes efficient planarization of the surface of difficult-to-process materials.Based on the pseudo-static matrix method,the static and dynamic models of the stage are established.Based on FEA and whale optimization algorithm(WOA),the sizes of the stage are optimized,and then the theoretical statics and dynamics performance of the stage are determined.(2)Performance verification of the asymmetric vibration-assisted stage.Based on finite element analysis(FEA)and performance test,the statics and dynamics performance of the stage are verified,especially,the characteristics of asymmetric displacement and asymmetric stiffness are verified.Based on the polishing experiment,it is verified that the stage can effectively remove the single-directional surface textures of difficult-to-process materials,and meet the technical requirements of the photocatalytic-roll-vibratied complex polishing.(3)Study on oxidation of photocatalytic-roll-vibratied complex polishing.Based on methyl orange degradation and REDOX reaction rate characterization experiments,the effects of photocatalysis and vibration on degradation time and REDOX reaction potential(ORP)are studied.The improvement of photocatalysis and vibration can effectively improve the oxidation of photocatalytic reaction.Based on nano-indentation experiments,the effects of photocatalysis and vibration on mechanical properties of silicon carbide are studied.The oxidation law and processing effectiveness of the photocatalytic-roll-vibratied complex polishing are clarified.(4)Removal characteristics of the photocatalytic-roll-vibratied complex polishing.The removal mechanism of the polishing technology for difficult-to-process materials are studied.The key elements of the photocatalytic-roll-vibratied complex polishing are clarified.The photocatalytic-roll-vibratied complex polishing stage is built.For silicon carbide,the photocatalytic-roll-vibratied complex polishing experiments are carried out,and the effects of photocatalytic and vibration on polishing effects are analyzed.The effects of photocatalytic parameters(light intensity)and vibration parameters(frequency and amplitude)on the surface roughness,surface peak-valley value and material removal rate of the polishing are studied.