Simulation And Experimental Study Of Flow Field During Hydrodynamic Suspension Polishing

Nano-film material is a new material with special structure. It will be more and more valuable for its excellent electrical, magnetic, optical and mechanical properties in rapidly rising electronic industry. The surface morphology of nano-film substrate will obviously influence the surface morphology largely depends on atomic layer stacking patterns and growth direction, so it has a huge impact on comprehensive performance of nano-film products. There are many methods to prepare nano-film substrate at this stage, but there are still some shortcomings.In this paper, in order to prepare ultra-smooth substrates of nano-film, a new polishing method—hydrodynamic suspension polishing is proposed. The purpose of this method is to improve liquid-carrying capacity and the processing of polishing liquid pressure distribution to achieve ultra-smooth substrates of nano-film. The main contents of the paper are:(1) Motion state of free abrasive when polishing and the theory of removing material have been analyzed. Comparing the advantages and disadvantages of three kinds of flow passage structure by two-dimensional simulation, some insufficiencies were found, so a new polishing tool disc with contained boundary was put forward.(2) The influence of structure parameters of polishing tools disc and processing parameters on liquid pressure can be obtained by simulating the model of three dimensional flow fields using the FLUENT software. The effect of suspension abrasive on the pressure of polishing liquid and the movement of suspended abrasive can be obtained by two-phase flow simulation.(3) In order to monitor liquid pressure under different processing parameter for a real-time, a hydrodynamic suspended polishing device with liquid pressure detection device was constructed. Firstly, the sample processing has been preprocessed by mechanical polishing. Subsequently, the ultra-smooth surface processing has been processed by hydrodynamic suspended polishing. Sub-surface qualities before and after sample processing were characterized and compared by TEM to verify the advantage of hydrodynamic suspended polishing technique. Results showed that the atomically ultra-smooth surface can be prepared by the present novel polishing technique.