Study On Machining Relationships And Mechanism Of WEDM In Gas

Along with science technology developing and environmental consciousness rising, Wire Electrical Discharge Machining (WEDM) to micronization, intellectualization, highly effective and green environmental protection tendency rapid advance. Dry WEDM is a kind of newly developed green machining technology that uses gases as dielectric. Comparing with conventional liquid dielectric, the new method has the advantages of better surface straightness, smaller gap length, no electrochemical corrosion and environmental friendly in processing, so it is suitable for multiple cutting and finishing cutting in WEDM.In this article the theory of high-speed WEDM (HS-WEDM) were summarized, and analysis the basic forms of gases dielectric conductance and breakdown and discharge mechanism of WEDM based on the EDM. Moreover, the multiple cutting processes in WEDM, the multiple finishing cutting technology of HS-WEDM in gas and the machine used in experiments and surface measuring machine were also be introduced.In this research typical mould steel Cr12MoV was chosen as the test material, based on first cutting in liquid the orthogonal design and uniform design were taken in second cutting, and through analyzing the results of orthogonal test by the method of rang analysis and variance analysis the significance between process index and factors were acquired; Meanwhile, the multivariate nonlinear regression analysis was taken in the data of uniform by the method of stepwise, and the experimental formula of the relationship between factors and process indexes were done, the verification test and typical shape parts were also have done.In the view of mechanism research of EDM in gas, physical and mathematics model of single pulse EDM is built, suitable heat resource form has been selected and the transient thermal field of single pulse in gas was analyzed. Thermal field and strain and thermal stress on the work-piece material which was founded under the action of transient thermal was obtain through the thermal field which was simulated by finite element ANSYS package.