磁场对电火花放电通道的影响研究

放电过程中的横向静磁场可使带电粒子受到洛伦兹力而改变运动轨迹,造成工件上放电点的位置变化,进而引起电蚀坑形貌的变化。利用理论方法推算出磁场作用下的电子运动轨迹,得到工件上放电点的理论偏移值,并通过实验证明洛伦兹力改变了放电点的位置。结果表明:部分电蚀坑出现明显的拉长型畸变,放电点沿洛伦兹力方向移动,放电通道在洛伦兹力与工作液阻力的作用下逐渐发生偏移。电蚀坑被拉长后其深度会变浅,大而浅的电蚀坑将有助于提高电火花加工的表面质量。

Study on the Influence of Magnetic Field on the Discharge Channel of EDM

The trajectory of charged particles will be changed because of lorentz force from horizontal static magnetic field ,and this will cause the position of the discharge point on the workpiece to change,then the shape of discharge crater will become deformed. This paper proposes the theoretical trajectory of electrons in magnetic field ,and then proves that lorentz force is reason why position of discharge point changes by means of experiment. The result of this experiment indicates that some of discharge craters are elongated,and the elongating direction is the same with direction of lorentz force, the discharge channel gradually become offset with the influence of lorentz force and fluid resistance. The depth of elongated discharge craters will become shallower ,and the shallower discharge craters may improve the surface quality of EDM.