# Experimental Study on Milling CFRP with Staggered PCD Cutter
## 1 Introduction  
Carbon fiber reinforced plastic (CFRP) is widely used in such fields as aviation equipment, space vehicles, new weapons, etc. due to its excellent physical properties, such as high specific strength, high specific modulus and fatigue resistance, etc. [1; 2]. However, with higher and higher demand for the processing and assembly of high-modulus CFRP in the industrial field, the problem of cutting CFRP becomes increasingly salient. For instance, the control of such defects as cutting delamination, tearing and burr etc. [3], and the improvement of tool durability, have become key limitations in the application of high-quality machining technology of CFRP materials.  
A great deal of research on the cutting technology of CFRP has been carried out by scholars at home and abroad. [PERSON] et al. [4] investigated the occurrence reasons and extension law of cutting delamination through an experiment in which CFRP was milled using a two-flute PCD cutter, and the results showed that the delamination was highly dependent on the fiber orientation and tool edge sharpness. Moreover, the occurrence zone, diffusion zone and non-diffusion zone of defects were divided. [PERSON] et al. [5] used two different PCD cutters to millidirectional CFRP in tests, based on which the milling force prediction model was established, and the influence law of milling force on machining surface quality was obtained. [PERSON] et al. [6] studied the tool wear formsunder various cooling conditions, and the results indicated that air cooling conditions can effectively minimize the heat generated in processing and the area of the tool wear zone, and prolong tool life. [PERSON] et al. [7] carried out the experiment of milling CFRP using tools coated with diamond, and found that smaller milling forces and greater machining surface quality is satisfactory under the high-speed and low-feed cutting conditions. [PERSON] et al. [8] established a 3D finite element model for cutting unidirectional CFRP, and the simulation results showed that fiber orientation angle, cutting depth and cutting speed are the main influential factors of milling force and surface roughness. [PERSON] et al. [9] conducted an experimental study on milling CFRP with a PCD cutter, and established the milling parameter optimization model for machining surface quality. [PERSON] et al. [10; 11] carried out a test in which milling of CFRP was performed with a coated carbide tool, and investigated the influential mechanism of cutting parameters on cutting force, cutting temperature and machining surface quality. Meanwhile, the finite element method was used to predict cutting force and surface roughness. [PERSON] et al. [12; 13; 14; 15; 16] conducted relative studies on the machining performance of the composites and optimization of cutting parameters.  
In conclusion, the current research on milling CFRP mainly focuses on the cutting mechanism and machining surface quality [17; 18; 19; 20], and cutting tools are mostly straight-teeth PCD or coated with carbide diamond [21; 22]. Compared with the straight-teeth tools, staggered cutters have the advantages of reducing cutting resistance and restraining burr formation through bidirectional alternate inclination angle structure in the process of cutting CFRP, which has attracted significant attention from researchers [23]. Thus, in this paper the experiment of milling CFRP with staggered PCD cutters was carried out, and the wear extension law of PCD cutters and the influential mechanism of tool wear on machining surface quality was studied. Finally, the cutting performance of straight-teeth and staggered PCD cutters is compared and analyzed.