Fig. 1. Heat transfer model of carbon fiber insulation felt

Fig. 2. Beam intensity distributions. (a) Input beam; (b) output beam

Fig. 3. Radial Raman test diagram of carbon fiber insulation felt

Fig. 4. Carbon fiber insulation felt surface temperature. (a) Measured temperature field distribution; (b) three-dimensional temperature distributionn

Fig. 5. Laser graphitized carbon fiber insulation felt device

Fig. 6. Carbon content of PAN-based carbon fiber insulation felt. (a) Before irradiation; (b) after irradiation

Fig. 7. Change of carbon content in each layer of PAN-based carbon fiber insulation felt

Fig. 8. Raman spectrum peak fitting curves. (a) Before laser irradiation; (b) After laser irradiation

Fig. 9. Graphitization of carbon fiber insulation felt under different laser power densities. (a) Raman spectra of irradiated surface;

Fig. 10. Surface morphologies of carbon fiber insulation felt monofilaments under different laser power densities. (a) Before irradiation; (b) 760 W/cm²;(c) 880 W/cm²; (d) 1000 W/cm²; (e) 1120 W/cm²; (f) 1240W/cm²

Fig. 11. Graphitization of carbon fiber insulation felt under different irradiation time. (a) Raman spectra of irradiated surface; (b) radial graphitization degree