Wear mechanisms and tool life management of WC–Co drills during dry high speed drilling of woven carbon fibre composites
Wear mechanisms and tool life management of WC–Co drills during dry high speed drilling of woven carbon fibre composites
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DOI：
10.1016/j.wear.2009.01.031
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发表时间：
2009-06
期刊：
影响因子：
5
通讯作者：
S. Rawat;H. Attia
中科院分区：
文献类型：
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作者：
S. Rawat;H. Attia
编织碳纤维复合材料广泛应用于航空航天、汽车和民用领域。复合材料高速钻削工艺的优化是一个具有重大经济意义的问题。刀具磨损和零件质量是定义优化方案的目标函数和约束的核心。本文研究了硬质合金（WC）钻头在高速干式钻削准各向同性编织石墨纤维环氧复合材料时的磨损机理。使用标准双槽钻头，在高达15，000rpm的主轴速度下评估工具磨损。本文探讨了这个摩擦系统的非线性行为和相互依赖的磨损过程和切削力的表面损伤的系统组件。研究发现，崩落和磨损是控制WC钻头失效的主要机制。两个摩擦制度，轻，重载，被发现支配力的增加，复合材料的分层和表面粗糙度。断裂的石墨纤维和WC颗粒对软环氧树脂基体的侵蚀性摩擦引起高温升高，从而加剧了后刀面磨损。在第一和第二磨损阶段，磨损的后刀面上的主切削刃被发现是占主导地位的，而碳的粘附被发现发生沿着与第三区的磨损。工具寿命的结果显示，从初级过渡到三级磨损制度的分层和表面粗糙度的增加。建立了刀具磨损、分层损伤和表面粗糙度之间的相关性。最后得出结论，可以通过监测切削力来设计刀具更换策略。
Woven carbon fibre composites are extensively used in aerospace, automotive and civil applications. Optimization of high speed drilling of composites is an issue of great economical impact. Tool wear and part quality are central to the definition of the objective function and constraints of the optimization scheme. This paper presents an experimental investigation of the wear mechanisms of tungsten carbide (WC) drills during dry high speed drilling of quasi-isotropic woven graphite fibre epoxy composites. Tool wear was evaluated at spindle speeds of up to 15,000rpm using a standard two flute drill. The paper examines the nonlinear behavior of this tribo-system and the interdependence of the wear process and cutting forces in relation to surface damage of the system components. It was found that chipping and abrasion were the main mechanisms controlling the deterioration of WC drill. The two friction regimes, the lightly and heavily loaded, were found to dictate the increase in forces, delamination of composite and surface roughness. The aggressive rubbing by fractured graphite fibres and WC grains against the soft epoxy matrix caused high temperature rise and consequently enhanced flank wear. During the primary and secondary wear stages, wear on the flank face of main cutting edges was found to be dominant, while adhesion of carbon was found to occur along with abrasion in the tertiary zone. Tool life results revealed the increase in the delamination and surface roughness with transition from the primary to tertiary wear regime. The correlation between tool wear, delamination damage and surface roughness was established. Finally it was concluded that a tool replacement strategy could be devised by monitoring the cutting forces.