碳纤维增强复合材料电火花加工温度场仿真及材料蚀除机理研究

摘要

Carbon fiber reinforced plastic (CFRP) has high specific strength,specific stiffness,high hardness and other excellent characteristics. However,due to the special properties of the material, traditional cutting machining often causes delamination,cracking,burrs and other machining defects. EDM is an effective alternative for machining difficult-to-cut materals,and has the feasibility of machining CFRP. The temperature field of CFRP in a single pulse discharge was simulated,and the material removal mechanism was analyzed. It was found that the shape of the discharge crater is related to the machining direction. When the machining direction was parallel to the carbon fiber,the discharge crater was circle,and the depth of the crater was deeper. When the machining direction was perpendicular to the carbon fiber,the discharge crater was ellipse,and the discharge crater's depth was shallower. Moreover,during the discharge machining,the resin material in the heated region was much more removed,while the carbon fiber was remained and exposed on the surface of the discharge crater.%碳纤维增强复合材料(CFRP)具有高比强度、高比刚度和高硬度等优异特性,但由于该材料的特殊性质,采用传统的切削加工会出现分层、开裂、毛刺等加工缺陷.电火花加工技术适合加工难加工材料,具有加工CFRP的可行性.通过对CFRP进行单脉冲放电温度场仿真研究,分析其放电蚀除机理.结果表明:放电凹坑形貌与加工方向有关,当加工方向与碳纤维平行时,放电凹坑呈圆形且深度较深;当加工方向与碳纤维垂直时,放电凹坑呈椭圆形且深度较浅;此外,放电蚀除过程中受热区域的树脂材料蚀除较多,而碳纤维则会残留并裸露在放电凹坑表面.