## 1 Introduction  
SiC-particulates-reinforced Al matrix composites (SiC\({}_{\text{p}}\)/Al composites) possess many excellent physical and mechanical properties compared with conventional metal materials, such as high specific modulus, enhanced resistance to wear, low thermal expansion, and high thermal conductivity [1; 2; 3]. They have been widely used in aerospace structures, turbine engine blades, electronic packaging, satellite bearings, laser reflectors, and nuclear engineering [4; 5]. However, due to the addition of the rigid ceramic particles, a material with low fracture toughness that is typically hard-brittle and difficult to cut, the machining of SiC\({}_{\text{p}}\)/Al composites is very difficult, and the main difficulties lie in low surface precision and poor edge quality. In a wide definition, the edge defects are seen as undesirable effects generated at the exit end of the workpiece during the machining process. The edge defects not only have a negative effect on the dimensional precision of parts, but also easily cause the early failure of SiC\({}_{\text{p}}\)/Al composite parts in the service process, and can usually not be repaired. It is well-known that machined surface integrity is the result of the combined action of many factors, such as machining parameters, part materials, the material and geometries of the tool, as well as cooling and lubricating conditions. In past decades, many studies have been conducted on the machining characteristics of SiC\({}_{\text{p}}\)/Al composites, mainly referring to tool wear, chip formation, and surface quality (e.g., dimensional precision). [PERSON] et al. [6], [PERSON] et al. [7; 8], and [PERSON] et al. [9] have explored the effects of tool materials on tool wear behaviors when machining SiC\({}_{\text{p}}\)/Al compositesunder different cutting conditions. These studies revealed that the tool life considerably decreased with the increase of cutting speed and reinforced particle size. Several researchers [10; 11; 12] have analyzed the influence of tool materials and cutting parameters on surface roughness and subsurface damage when cutting SiC\({}_{\text{p}}\)/Al composites, and concluded that high cutting speeds and low feed rates produced higher surface quality, and if SiC particles were removed by pressed-into or cut-through mechanisms, good surface finish would have been achieved. [PERSON] et al. [13] investigated the mechanism of chip formation during the cutting of SiC\({}_{\text{p}}\)/Al composites, and showed that both cutting speed and feed rate had a very significant influence on the chip segment. Moreover, burr formation and delamination in the machining of ductile material and fiber-reinforced composites have been reported. [PERSON] et al. [14] explored machined surface defect formation of SiC\({}_{\text{p}}\)/Al composites at nanoscale using molecular dynamics simulation and an ultra-precision turning test, and revealed the brittle-ductile machining mode transition mechanism. [PERSON] [15; 16] studied the formation mechanisms of burr and edge breakout in metal cutting, and proposed some burr/breakout formation models for orthogonal cutting. The modelling of 2D and 3D oblique cutting were conducted by [PERSON] et al. [17] and [PERSON] et al. [18], respectively, and it was found that the burr size and fracture location increased as the inclination angle decreased. In addition, there has been much research upon the drilling-induced delamination characteristics on the hole entry and exit ends when machining fiber-reinforced composites [19; 20; 21; 22; 23]. However, the machining of SiC\({}_{\text{p}}\)/Al composite is still a challenging task in automotive and aerospace applications due to its complex edge defects. Up to now, scarce research has comprehensively revealed the edge quality and its influencing factors when turning SiC\({}_{\text{p}}\)/Al matrix composites, and the edge defect formation mechanism of turning SiC\({}_{\text{p}}\)/Al composite is believed to be different when compared to the other machining methods.