Simultaneously enhanced printing efficiency and conductivity of carbon black-reinforced PA1212 composites with network microstructures fabricated by selective fiber laser sintering

Due to its flexibility, ease of handling, and cost-effectiveness, long-chain polyamide powder (PA12/PA11/PA1212) fabricated by additive manufacturing is widely utilized in various industries. However, there is a need for further improvement in the mechanical strength and conductivity of long-chain polyamide powder prepared by SLS. In this study, we employed the selective laser sintering technique (SLS) equipped with a fiber laser to process carbon black (CB)-reinforced PA1212 powder composites. Our results indicate that CB plays a crucial role in enhancing the absorption rate of laser energy. CB significantly enhances absorption efficiency at 1080 nm in PA1212-C composites, with a 0.4 wt% CB content achieving optimal conversion efficiency. The mechanical properties of sintered polyamide components were significantly enhanced when sintered at a power of 120 W using high-speed printing techniques, with SLS utilizing fiber laser technology proving to be one-third more efficient than traditional SLS methods. When the CB content reached 1.6 wt%, the conductivity of the CB-based polymer composite parts achieved a value of 2.1 × 10⁻⁵ S/cm, indicating percolation behavior. This study demonstrates the feasibility of preparing CB-based polymer composites using fiber lasers through selective laser sintering technique, thereby expanding their potential application scope.