Research On Thermal Effect And Countermeasure Of Atmospheric Inductively Coupled Plasma Processing

In order to meet the demand of high efficiency and high precision in the optical manufacturing requested by the science engineering such as Inertial Confinement Fusion,space observation,aerospace field,etc,there are many ultra-smooth surface machining technologies in the optical fabrication.As a new innovative technology based on the chemical reaction,atmospheric plasma processing technology has the advantages of high processing efficiency,no damage layer and low cost by using the reaction between the activated particles and materials to realize the removal of materials.At present,there are many kinds of plasma sources,including capacitively coupled plasma,inductively coupled plasma,etc.Compared with the former,on the one hand,the excitation of the inductively coupled plasma can avoid the electrode pollution,and the plasma jet energy is high,which greatly improves the removal rate of materials.On the other hand,the thermal effect caused by high temperature and high enthalpy of plasma jet restricts the high-precision machining of optical components.Based on the heat transfer theory,in this paper,the establishment of heat transfer modle,simulation analysis and experiment research are conduct ed.Then the thermal effect in the processing are summarized by experiments.Aiming at conformal processing,the effective method for avoiding the thermal effect is given through the simulation parameters control.Firstly,based on the energy balance in the generalized low-temperature plasma processing,the suitable boundary conditions are selected and the heat transfer model in the jet processing is established.Through FLUENT finite element analysis software and the heat transfer theory in the flow field,the surface jet characteristics of components are analyzed.The heat flux density on the surface of the components under different machining conditions is acquired by conducting a steady-state temperature measurement experiment.Then,based on COMSOL software,the temperature field changes in the components under the action of jet flow were dynamically analyzed.The influence of processing parameters on components temperature was analyzed by parametric scanning.In order to further reduce the surface temperature of components during processing,two cooling methods are proposed and their effectiveness is analyzed by simulation.Finally,the dynamic temperature prediction of the heat transfer model is verified by experiment and the error analysis is carried out.The process experiments were carried out to summarize the thermal effect of temperature on the surface shape and removal efficiency of the components during the processing.In order to achieve uniform removal in conformal processing,combined with temperature field simulation,the countermeasure of thermal effect based on parameter control was proposed and verified by experiments.