不同排屑条件对叠层构件螺旋铣孔质量及刀具磨损的影响

Influence of Different Chip Removal Conditions on Hole-Making Quality and Tool Wear in Helical Milling of CFRP/Ti Stacks

现代飞机装配过程中,有大量碳纤维增强复合材料/钛合金(CFRP/Ti)叠层构件的制孔需求,复合材料及钛合金的难加工性使得叠层构件制孔成为影响飞机装配周期和装配质量的重要因素。螺旋铣孔技术因其较小的轴向力、较好的散热性和排屑性得到广泛关注。但基于孔加工过程封闭的切削环境,螺旋铣孔还是无法避免加工过程孔内残留切屑问题。针对以上问题,本文通过竖直螺旋铣孔实验,对比研究了自然排屑和使用集屑装置时孔壁粗糙度、孔径精度、孔出入口缺陷以及刀具磨损等。结果显示,集屑装置可避免切屑在孔口的堆积,进而减少向孔内返屑现象,从而有效降低因碳纤维和钛合金切屑导致的刀具磨损,提高孔径精度,减少孔出口缺陷。

There are a large number of holes to be machined on carbon fiber reinforced plastic/titanium alloy (CFRP/Ti) stacks in modern aircraft assembling. Due to the hard machinability of CFRP and titanium, hole-making process on the stacks becomes an important factor affecting assemble time and quality. Helical milling has attracted much attention for its low axial force, good heat dissipation and smooth chip removal. However, the problem of residual chips in the hole during helical milling process still arises because of the relatively closed machining environment. In this paper, hole side wall roughness, hole diameter, defect on hole exit and tool wear produced with and without a chip collector were investigated comparatively. Results show that the chip collector can promote chip removal and eliminate the chip accumulation around the hole entrance. Consequently, the chip return phenomenon was lessened, tool wear was decreased and hole quality improved.