CFRP及叠层结构螺旋铣孔专用刀具切削性能评价

碳纤维增强复合材料(CFRP)及由钛合金Ti-6Al-4V和CFRP组成的金属复合材料叠层结构广泛应用于现代航空工业。大型客机结构件之间主要通过铆接和高锁螺栓连接,根据波音与空客公司发布的数据显示,最新一代B787与A380上装配孔的数量已超百万,装配过程中的制孔效率与质量直接决定了客机整体装配效率及关键结构件的疲劳寿命,从而间接影响了客机的生产成本以及飞行可靠性。随着飞机数字化装配的快速发展,传统的钻孔工艺会产生很多加工缺陷,工序复杂,加工孔质量不能满足要求,因此,有必要优化制孔工艺,设计新型专用刀具。本文通过研究螺旋铣孔运动学特性,分析螺旋铣孔的工艺特点,设计了一种新型螺旋铣孔专用刀具,并以加工过程的轴向切削力、出入口加工质量以及刀具磨损为评价指标,验证该新型专用刀具的切削性能。结果表明,专用刀具在干切削条件下能够实现复材孔无分层、钛合金孔无毛刺加工,大幅提高刀具寿命,解决了传统立铣刀对CFRP及CFRP/钛合金叠层结构进行螺旋铣孔时刀具寿命低、加工质量差等问题。

Cutting Performance Evaluation of Helical Milling Specialized Tool for CFRP and CFRP/Titanium Alloy

Carbon fiber reinforced plastics(CFRP)and metal composite laminate structures composed of titanium alloys Ti-6Al-4V and CFRP are widely used in the modern aviation industry.Structural parts of large passenger aircraft are mainly linked by riveting and high-lock bolts.According to data released by boeing and airbus,the number of mounting holes on the latest generation of B787 and A380 has exceeded one million.The efficiency and quality of the hole making during the assembly process directly determines the overall assembly efficiency of the passenger aircraft and the fatigue life of the critical structural components,which indirectly affects the production cost and flight reliability of the passenger aircraft.With the rapid development of digital assembly of aircraft,traditional drilling and hole making will produce many processing defects and cannot meet the processing requirements.Therefore,it is necessary to optimize the hole making process and design the specialized tool for CFRP and the laminated structure.According to the kinematics of spiral milling,a new specialized tool for spiral milling is designed,and the axial cutting force,the quality of the inlet and outlet,and the wear of the tool are verified.The results show that the specialized tool can realize the delamination-free of the composite hole and the burr-free of the titanium alloy hole under dry cutting conditions,and the tool life is greatly improved.It solves the problems of short tool life and poor processing quality when the conventional end mill is used for spiral milling on CFRP and CFRP/titanium alloy laminated structures.