Thermal protection behavior of Al/graphite/Al laminated composites subjected to laser irradiation: Mechanism of anisotropic heat flow redirection

This paper presents the fabrication of the Aluminum/Graphite/Aluminum composite with high-power laser protective capability through the optimized vacuum hot pressing. The effects of key parameters in the vacuum hot-pressing process, specifically the hot-pressing temperature and holding time, on the interfacial bonding performance of Aluminum/Graphite/Aluminum composites are investigated. The high-power laser experiments are established to investigate the effects of processing parameters and interfacial phase evolution on interlayer bonding strength, in-plane thermal conductivity, and structural burn-through behavior. The results show that optimal processing conditions (725 °C and 100 min) achieve a favorable balance between melting and interfacial bonding. The formation of Al 4 C 3 simultaneously enhances interfacial strength and inhibits through-thickness laser energy transport due to its low thermal conductivity, thereby improving the laser protection performance of the composite. Compared with the aluminum alloy, the burn-through time of composite increases from 9.70 s to 12.95 s at the laser power density of 1909 W/cm 2 . While the monolithic aluminum alloy burned through at 8.2 s under 5092 W/cm 2 , the composite resisted burn-through throughout the full 15.0 s irradiation. The Aluminum/Graphite/Aluminum composite fabricated by optimized vacuum hot pressing can effectively regulate the heat diffusion pathway, enhance in-plane heat dissipation, and retard through-thickness heat transfer, thereby significantly improving the laser protection capability.