Compounding Magnetic On EDM Surface Strengthen And Experimental Study

The application of the electrical discharge machining (EDM) is more andmore widely used with the maturing of electrical discharge machiningtechnology. Electric spark machining technology has been applied in the field ofsurface strengthening successfully and obtained some good results.A new method of surface strengthening by ordinary high-speed ElectricalDischarge Machining(EDM) hole processing tool is described based on thetheory of electric spark deposition, so tungsten carbide reinforced layer onsurface of45#steel can be obtained by changing the polarity in the air dielectricafter surface deposition technology. This paper analyzes the influence of variousprocess parameters on the sediment quality from three aspects of the roughness,thickness and micro sedimentary defects. After experimental analysis,2currentfile and5pulse width file was chosen to get the optimal sediments ofcomprehensive quality, its thickness can reach to35μm and its hardness is1000HV without visible flaws of tungsten carbide sedimemt.The problem of deposition coating is that the sedimentary thickness is smalland the surface roughness is big by ordinary EDM tool, so people have done lots of experimental research to solve this problem. This paper presents a newdepositing method by compounding permanent magnetic and EDM. Throughthe role of permanent magnetic field, the magnetic workpiece is magnetized, sothe magnetic materials receive a downward force thus making them difficult todeviate from the workpiece surface, this can make the thickness of sedimentincreased, the surface roughness reduced and the utilization factor of materialincreased.When the processing is drastic, the thickness of strengthening layer we gotis large but the roughness is also very large. In order to get large sedimentthickness but small surface roughness of strengthening surface. This paperfinally adopts two optimization schemes, one is that processing surface usingsmall electrical parameter on the surface processed by big electrical parameter.The other is using the barrelling equipment for surface finishing machining afterthe surface has been processed by big electrical parameter. The experimentalresults show that the two optimization schemes can reduce the surfaceroughness and hardly change the thickness.