# Study of Surface Defect Detection Techniques in Grinding of SiCp/Al Composites
## 4 Influence of Machining Parameters on Surface Quality
### Analysis of the Effect of Grinding Parameters  
Figure 11 shows the effect of grinding parameters, including spindle speed, feed rate, cutting depth, and ultrasonic vibration amplitude, on the total defect area and the number of defects in the machining region. From Figure 11a, both \(A_{\mathrm{t}}\) and \(N_{\mathrm{d}}\) show a significant downward trend with the increase in spindle speed. This is due to the fact that for a given material removal volume, an increase in spindle speed will cause a rise in the number of abrasive grains involved in the cutting zone and, therefore, the cutting volume of individual abrasive grains decreases. This will reduce the cutting force and improve the surface quality. The increase in spindle speed also shortens the effective cutting time of individual abrasive grains, meaning that the heat generated in the shear zone cannot be dissipated in time. A high temperature makes the material softer and easier to process, and this is helpful for improving the surface quality. Figure 11b shows the effect of the feed rate on \(A_{\mathrm{t}}\) and \(N_{\mathrm{d}}\). \(A_{\mathrm{t}}\) and \(N_{\mathrm{d}}\) are found to increase as the feed rate increases from 15 to 20 mm/min, and then, they remain stable until the feed rate reaches 30 mm/min. The \(A_{\mathrm{t}}\) increases significantly when the feed speed is increased from 30 to 35 mm/min. As the feed rate increases, the thickness of the undeformed chips increases, leading to a larger removal volume for a single abrasive grain and therefore resulting in an increase in grinding force. The increase in grinding force leads to an increase in interfacial failure between the silicon carbide particles and the \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**No.** & \(\mathbf{n}\) **(rm)** & \(\mathbf{v_{f}}\) **(mm/min)** & \(\mathbf{a_{p}}\) **(\(\mathbf{\mu}\))** & \(\mathbf{A}\) **(\(\mathbf{\mu}\))** & \(\mathbf{d}\) **(mm)** & \(\mathbf{S_{a}}\) **(\(\mathbf{\mu}\))** & \(\mathbf{A_{\mathrm{t}}}\) **(\(\mathbf{\mu}\)2)** & \(\mathbf{N_{\mathrm{d}}}\) **(\(\mathbf{\mu}\)2)** & \(\mathbf{N_{\mathrm{d}}}\) **(\(\mathbf{\mu}\)3)** \\ \hline
1 & 3000 & & & & & & & 57,222.57 & 7 \\
2 & 6000 & & & & & & & 53,182.92 & 9 \\
3 & 9000 & 25 & 10 & 5 & 4 & 54 & 38,162.55 & 6 \\
4 & 12,000 & & & & & & 27,794.07 & 4 \\
5 & 15,000 & & & & & & 11,264.24 & 2 \\ \hline
6 & & 15 & & & & & 18,171.58 & 3 \\
7 & & 20 & & & & & & 25,998.80 & 4 \\
8 & 12,000 & 25 & 10 & 5 & 4 & 54 & 27,794.07 & 4 \\
9 & & 30 & & & & & 26,990.74 & 4 \\
10 & & 35 & & & & & 50,823.62 & 5 \\ \hline
11 & & & 5 & & & & 19,626.48 & 3 \\
12 & & & 10 & & & & 27,794.07 & 4 \\
13 & 12,000 & 25 & 15 & 5 & 4 & 54 & 17,311.28 & 3 \\
14 & & & 20 & & & & 28,022.15 & 4 \\
15 & & & 25 & & & & 39,889.16 & 5 \\ \hline
16 & & & & & 0 & & & 39,159.21 & 5 \\
17 & & & & 1.25 & & & 42,518.35 & 6 \\
18 & 12,000 & 25 & 10 & 2.5 & 4 & 54 & 42,178.25 & 5 \\
19 & & & & 3.75 & & & 27,794.07 & 4 \\
20 & & & & & 5 & & 22,950.30 & 3 \\ \hline
21 & & & & & & 2 & 18,920.75 & 2 \\
22 & & & & & & 4 & 27,794.07 & 4 \\
23 & 12,000 & 25 & 10 & 5 & 5 & 4 & 54 & 27,794.07 & 4 \\
24 & & & & & & 6 & 37,205.05 & 5 \\
25 & & & & & & 8 & 34,603.97 & 4 \\ \hline
26 & & & & & & & 46 & 23,465.70 & 3 \\
27 & & & & & & & 54 & 27,794.07 & 4 \\
28 & & & & & & & 64 & 31,812.16 & 4 \\  & & & & & & & 76 & 49,643.07 & 6 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Statistical results for \(N_{\mathrm{d}}\) and \(A_{\mathrm{t}}\). aluminum alloy matrix, so the silicon carbide particles can be easily broken or pulled out, thus increasing \(N_{\mathrm{d}}\) and \(A_{\mathrm{t}}\).