Influence Of Bottom Step Characteristics On Fluid Pressure Drop In Micro Channel Machined By EDM Milling

Microchannel is a kind of micro three-dimensional structure with the function of reducing pressure and throttling,which is widely used in pressure controller,heat exchanger and other parts.Electric discharge machining(EDM)milling is widely used in the processing of micro-three-dimensional structures because of its non-contact processing,no obvious macroscopic force,and no limitation of the strength and hardness of the workpiece material.Therefore,EDM milling technology is an effective way of micro-channel machining,but in the process of micro-channel machining,due to tool electrode wear,step-like undulating characteristics will be formed at the bottom of the micro-channel.From the perspective of the influence of step characteristics on fluid pressure drop.The spiral microchannel is machined by using the EDM milling technology,and the simulation analysis and experimental research are carried out on the step characteristics produced by the EDM milling micro channel and its influence on the fluid parameters.The disadvantages of the steps which are not conducive to the forming process are transformed into advantages,and the influence of different step characteristics on the fluid pressure drop in the microchannel is explored.Firstly,the effects of electrode wear in EDM milling caused by pulse interval,pulse width and current were studied by single factor experiment.Based on the response surface method(RSM),the EDM milling experiment is carried out to explore the high efficiency and low wear EDM parameters to realize the spiral micro channel EDM milling.Secondly,the flow simulation model of spiral microchannel with bottom step characteristics is established to simulate the fluid pressure drop of spiral microchannel,and the influence of bottom step characteristics on the fluid pressure drop of spiral microchannel is analyzed.The flow field simulation of different step characteristic channel model and no step microchannel model was carried out,and the optimal depressurization parameters of the bottom step characteristics of spiral microchannel were explored to provide theoretical support for the optimization of spiral microchannel design.Finally,the micro electrode was prepared by block electrode discharge grinding(BEDG).The spiral micro channel was machined by using the micro electrode and high efficiency and low wear EDM milling parameters.