Experimental Study On Polishing Of Silicon Nitride Ceramic By Ultrasonic Fine Atomization

With the continuous development of new ceramic material,silicon nitride ceramic materials is getting more and more applications in industrial production for its excellent performance;but this ceramic material itself is relatively high in hardness,on the surface of the ultra precision machining,surface processing technology in general is easy to produce various surface defects on the surface of ceramic materials,and it is difficult to obtain high quality surface,and chemical mechanical polishing technology become an excellent way of ultra precision machining on the surface of silicon nitride ceramic materials due to the high quality of the advantages of processing efficiency,processing surface.Ultrasonic fine atomization liquid polishing technology can not only achieve the advantages of traditional chemical mechanical polishing technology,but also can reduce processing costs and avoid waste of resources.In this piece,the ultra fine machining of silicon nitride ceramic matrix was carried out by ultrasonic fine atomization liquid polishing technology,studied the optimization of the parameters of polishing slurry,the process parameters in the process of atomization polishing and the material removal mechanism of silicon nitride ceramics,lay the theoretical foundation for ultra precision machining of silicon nitride ceramic matrix in industrial production.(1)In this paper,the atomization polishing system used in the experiment was introduced,studied the effect of the single factor in the polishing solution on the polishing process,based on the material removal rate and the surface roughness of the polished silicon nitride substrate,through single factor experiment,the optimal value of the influence of various components in the polishing solution on the results of the polished silicon nitride ceramic substrate was screened out.(2)The orthogonal test method was used to optimize the parameters such as the mass fraction of the abrasive,the mass fraction of oxidant and the pH value of the polishing slurry,analyzed the influence of the value of each component of the polishing solution on the polishing result of the atomized polishing silicon nitride ceramic material and the material removal mechanism in the process of the atomization polishing.The optimized composition of the polishing slurry is the concentration of SiO2 is 6wt%,the content of hydrogen peroxide oxidant is 1wt%,and the pH value is 7.(3)In the case of other certain process parameters,studied the effects of three parameters,such as the mist flow rate,the polishing pressure and the rotating speed of the polishing pad,on the polishing effect of the fused silicon nitride ceramics under the condition of single factor test,the combination of the three process parameters was optimized by orthogonal test,and the best combination of process parameters was obtained,the optimum process parameters were 10.5 psi of polishing pressure,12.5 ml/min of mist flow rate,and the rotating speed of the polishing disk was 80 r/min.(4)Under the same experimental conditions,the ultrasonic fine atomized chemical mechanical polishing method and the traditional chemical mechanical polishing method were used to polish the silicon nitride ceramic substrate,and compared the experiment results of two different polishing methods.The experimental results show that the material removal rate of ultrasonic fine atomization CMP silicon nitride ceramic matrix is slightly lower than that of traditional CMP,and the surface roughness of two polishing methods is similar,however,the amount of polishing slurry used for atomization polishing is only 1/8 of traditional polishing.