## 3 Results and Discussion
### Thermal Conductivity of A-CF/EP/FEP Composites  
#### 3.4.1 Effect of A-CF on Thermal Conductivity of A-CF/EP/FEP Composites  
The TCs of pure EP, EP/FEP, and A-CF/EP/FEP were measured at room temperature (Figure 7). Like in other reports [29; 30], the TC of pure EP is 0.21 W/(m\(\cdot\)K). When 20% FEP was added into EP, the TC of the EP/FEP composite did not obviously change. On the contrary, TC decreased slightly to 0.19 W/(m\(\cdot\)K). After A-CF was added to EP/FEP composites, the TC increased significantly to 0.38 W/(m\(\cdot\)K) when the FEP content was 20%, which is 1.81 and 2.0 times those of the pure EP and the EP/FEP composite, respectively. The formation of an effective heat conduction path in materials such as EP and EP/FEP composites is a necessary condition for heat conduction, which will benefit phonon trans  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & \multicolumn{3}{c}{**Wear Rate Changes with Abrasion Cycles/Times**} & \multirow{2}{*}{**Friction Coefficient**} \\ \cline{2-2} \cline{4-5}  & **30,000** & **60,000** & **90,000** & **120,000** & \\ \hline A-CF/EP with PU of 2.0\% & 1.42 \(\times\) 10\({}^{-13}\) & 1.21 \(\times\) 10\({}^{-13}\) & 1.92 \(\times\) 10\({}^{-13}\) & 0.72 \(\times\) 10\({}^{-13}\) & 0.398 \\ A-CF/EP with PU of 4.0\% & 1.19 \(\times\) 10\({}^{-13}\) & 1.07 \(\times\) 10\({}^{-13}\) & 0.86 \(\times\) 10\({}^{-13}\) & 0.67 \(\times\) 10\({}^{-13}\) & 0.363 \\ A-CF/EP with PU of 6.0\% & 0.91 \(\times\) 10\({}^{-13}\) & 0.82 \(\times\) 10\({}^{-13}\) & 0.62 \(\times\) 10\({}^{-13}\) & 0.58 \(\times\) 10\({}^{-13}\) & 0.318 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Wear rates (10\({}^{-13}\).m\({}^{3}\).N\({}^{-1}\).m\({}^{-1}\)) and friction coefficients of the M-CF/EP composites with different contents of PU under the applied load of 2.8 MPa and sliding speed of 0.51 m s\({}^{-1}\).  
mission. For the A-CF/EP/FEP, the presence of A-CF contributes to the formation of a good heat conduction network.  
To visually evaluate the heat absorption capacity of samples, we recorded the infrared thermal images and the corresponding surface temperature changes in EP (a1), EP/FEP (a2), and A-CF/EP/FEP (a3) during the heating process. To ensure uniform and consistent temperatures, we placed all the composites on a heating plate and maintained room temperature or 80 \(\pm\) 2 \({}^{\circ}\)C for 1 h. During the heating (Figure 8a), the surface colors changed the fastest in A-CF/EP/FEP composites and the slowest in EP. In particular, the A-CF/EP/FEP composite rose from low temperature (blue) to high temperature (light pink) in the shortest time (Figure 8a). The endothermic efficiency of the samples is shown in Figure 8b. Clearly, when the heating time was 20 s, the surface temperatures of EP, EP/FEP, and A-CF/EP/FEP were 47.7, 55.9, and 62.2 \({}^{\circ}\)C, respectively. The A-CF/EP/FEP composite has a higher thermal management and heat transfer capacity compared with EP and EP/FEP.  
Figure 6: Surface SEM images of the A-CF/EP composites after 60,000 (**a**) and 120,000 (**b–d**) abrasion cycles at different magnifications.  
Figure 7: Thermal conductivity of pure EP, EP/FEP, and A-CF/EP/FEP composites with 20% FEP and 4% PU.