## 3 Results and Discussions  
It can be seen from the Figure 2 that under the condition of various pulse width which are from 0.5 ms to 2.5 ms, the time required for the braided CFRP surface to reach the maximum temperature decreases with the increase of laser energy density. Firstly, the pulselength dependence of laser processing CFRP material could be determined from Figure 2. It shows that with the increase of pulse width, the time required for the braided CFRP surface to reach the maximum temperature gradually increases. When the energy density is constant, the shorter the pulse width, the faster the heating rate. \begin{table}
\begin{tabular}{c c c} \hline \hline
**CFRP Material** & **Epoxy** & **Carbon** \\ \hline Thermal Conductivity (W/(m\(\cdot\)K)) & 0.2 & [60; 4; 4] \\ Density (kg/m\({}^{3}\)) & 1200 & 1500 \\ Heat capacity (J/kg\(\cdot\)K) & 1000 & 1000 \\ Lasers & & Value \\ Wavelength (nm) & & 1064 \\ Pulse length (ms) & & 1 \\ Pulse number & & 1, 5, 10 \\ Beam diameter (mm) & & 1 \\ Fluence (J/cm\({}^{2}\)) & & 100–1000 \\ Frequency (Hz) & & 10 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Parameters of CFRP material and lasers. Secondly, the laser fluence dependence of laser processing CFRP material could be figure out from Figure 2 as well. When the pulse width is constant, the time taken for the CFRP surface temperature rises to 3500 \({}^{\circ}\)C and decreases as the energy density increases, and the material heating rate becomes larger. When the energy density is low, the speed change is relatively obvious, and when the energy density is large, the speed change is relatively slow. When laser fluence increased from 80 J/cm\({}^{2}\) to around 250 J/cm\({}^{2}\), the time required to reach the maximum temperature when laser irradiated on CFRP was dropped rapidly. Moreover, when the laser energy density increases from 250 J/cm\({}^{2}\) to 700 J/cm\({}^{2}\), the time required for the braided CFRP surface to reach the maximum temperature decreases slowly. For example, for the case of 0.5 ms laser pulselength, the reducing time of 40 us needs only laser fluence of 100 J/cm\({}^{2}\) increasing at lower energy range, but needs more than 500 J/cm\({}^{2}\) increasing. This is mainly due to the fact that in the low laser energy density stage, the interaction between the laser and the braided CFRP is mainly endothermic heating, and the effect of heat conduction has not been shown. When the energy density is small, the epoxy resin on the surface of the CFRP material is decomposed by laser heating, and the decomposition rate is relatively slow. A large amount of heat is absorbed during the decomposition process, resulting in less laser energy for heating the carbon fiber, so the measured temperature rise is also slow. However, with the increase of laser energy density, the temperature on the surface and inside of CFRP rises sharply, forming a larger thermal gradient, and the role of heat conduction is more prominent. When the energy density is large, the laser irradiates the surface of the material, and the epoxy resin instantly vaporizes, so that the laser energy directly acts on the carbon fiber, and the fiber has a high thermal conductivity. Therefore, when the laser energy density is large, the temperature increase rate does not change significantly. When the heating effect and heat conduction of laser on CFRP tend to be in thermal equilibrium, the time required for the surface of woven CFRP to reach the maximum temperature hardly changes with the increase of laser energy density. Figure 3 shows the relationship between the heating time and the energy density of CFRP materials with different thicknesses under the action of 1 ms pulse width laser. The materials of different thicknesses have similar trends with the laser energy density, but the thicker target material heats up more slowly.