论文部分内容阅读
一、前言石墨材料具有很好的物理性能,它没有熔点、3500℃时开始升华、导热性能好而不会出现过热,故早已在电火花加工中被用来做电极材料。石墨的导电性能虽较金属差,但其比电阻还是比较低的;普通电火花加工中所用的电流密度还不致使石墨电极内部形成电阻热。
I. Preface The graphite material has good physical properties. It has no melting point and starts to sublimate at 3500 ℃. It has good thermal conductivity without overheating, so it has long been used as electrode material in EDM. Although the conductivity of graphite is worse than that of metal, its specific resistance is still relatively low. The current density used in ordinary EDM does not cause the resistance heat to form inside the graphite electrode.