## 3 Results  
### Groove Structures Processed with Different Scan Times by Conventional Laser Processing  
Figure 3 shows the workpiece morphology prior to cleaning after conventional laser processing. Each image shows the material after being processed a different amount of times. In each experiment, the processing area of the groove was 1.5 mm \(\times\) 3 mm. When the material was processed only 1 time, the material was obviously removed and the outline of the groove was clearly visible, as shown in Figure 3a. When the processing time increased to 50 times, the non-processing area around the groove became white, as shown in Figure 3b. With the continuous increase of processing scans, white products increased and clumped at local contours and gradually extended to the center of the groove (Figure 3c-e). When the processing times was 400 times, white products almost covered the entire area of the groove (Figure 3f). From the magnification of area A in Figure 3d, it can be observed that the white products were granular in the non-processing area outside of the groove, and extended to the processing area in a cluster, as shown in Figure 4.  
To observe the morphology of the workpiece under the white products, processed workpieces were cleaned in ethanol by ultrasound before SEM testing, and the results are shown in Figure 5. When the material was processed less than 100 times, workpiece surfaces were free of detritus, and the forming quality of the groove structure was excellent, indicating that the silicon carbide material was removed normally (Figure 5a-c). However, when the workpiece was processed 200 times, undesired deposits appeared on the sidewalls of the groove (Figure 5d). This can be explained by the presence of the white products shielding the material from the laser energy, and the deposits were melted and recast. It can  
Figure 3: Workpiece morphology processed a different number of times by conventional laser processing prior to cleaning: (**a**) 1 time, (**b**) 50 times, (**c**) 100 times, (**d**) 200 times, (**e**) 300 times, (**f**) 400 times.  
also be seen in Figure 5d-f that the recast molten deposits increased with processing times, and the distribution of deposits corresponded to the distribution of the cluster products.  
Next, the components of the different processed surfaces shown in Figure 5e were measured by EDS, and the white products on the workpiece surface before cleaning were also collected for EDS measurement. From Figure 6a, it can be concluded that the white products covered on the workpiece surface mainly consisted of Si and O, and also small amounts of C. Therefore, it can be inferred that the white products were mainly SiO2 and a small amount of SiC. The normally processed smooth surface at point B in Figure 5e contained a small amount of oxygen, as shown in Figure 6b, which was due to the oxidation reaction between the material and air during processing. For the surface of the recast deposit at point C in Figure 5e, the main components were C and Si. Therefore, the recast deposit was mainly SiC.  
Figure 4: Magnification of area A in Figure 3d.  
Figure 5: SEM of workpieces processed a different number of times by conventional laser processing after cleaning: (**a**) 1 time, (**b**) 50 times, (**c**) 100 times, (**d**) 200 times, (**e**) 300 times, (**f**) 400 times, B in (**e**) was the surface of normal machining, C in (**e**) was the surface of deposit.