碳纤维增强复合材料新钻型结构设计及其对比试验

New Drills Design and Comparative Experimental Research of Carbon Fiber Reinforced Plastics

在碳纤维增强复合材料(CFRP)制孔过程中,易产生毛刺、分层等制孔缺陷,而钻头结构是影响制孔缺陷形成的关键因素。对此,在原有钻型基础上设计了两种新钻型,研究了原有钻型和两种新设计钻型的钻削轴向力和制孔效果。结果表明,在相同钻削工艺参数下,原有钻型"V型"刃的修除阶段的轴向力归零速度最大,新设计的燕尾开槽钻型的最小,这与制孔缺陷的变化规律基本一致,轴向力归零速度与制孔缺陷具有较好的映射关系;3种钻型均能有效减少毛刺,与原有钻型相比,新设计的两种钻型均能更好的去除毛刺和降低制孔缺陷;原有钻型的制孔缺陷以撕裂为主,新设计的开槽新钻型和燕尾开槽新钻型则以分层缺陷为主。据此可为CFRP制孔的刀具结构设计提供新的设计思路。

During the drilling of carbon fiber reinforced polymer(CFRP),the defects,such as burrs and delamination,are prone to occur. The drill structure is a key factor influencing the formation of defects. Two new drills are designed according to the existing novel drill bit. The thrust forces and the performances of these drills are investigated. The results show that the thrust force degradation rate of the existing novel drill bit in the trimming stage of the"V-shaped"cutting edges is the biggest,and that of the newly designed swallowtail-grooved drill is smallest.These change rules of the thrust force degradation rates are basically the same as that of the defects. Then,the changes of the thrust force degradation rates have good mapping relations with the regularities of the defects. The burrs can be effectively reduced by using these three drills. Compared with the existing novel drill,the burrs and the delamination can be more effectively reduced by the two newly designed drills. The main defects form of the existing novel drill is the tearing,but the main defect forms of the two newly designed drills are the delamination. This paper provided a new design idea for the tool structure design of CFRP drilling.