Additive manufacturing of complex-shaped and high-performance aluminum nitride-based components for thermal management

Improved heat dissipation performance, by way of thermal management, is critical in many engineering applications. In this study, three types of silane coupling agents were used to modify aluminum nitride (AlN) powder for vat photopolymerization. The effect of silane coupling agents on the rheology, stability, and curing behavior were systematically studied. The results showed that, compared with two other types of silane coupling agents, one silane agent (KH570) had a larger positive effect on the rheology and stability of the AlN suspension, and the absorbance of the AlN powder increased after surface modification. In addition, the effects of different solid loadings on the curing behavior and C--C double-bond conversion rate were systematically investigated. It was found that a higher solid loading resulted in a lower curing depth, cure width, and C--C double-bond conversion rate. For the sintered AlN components with increased solid loading, the shrinkage decreased while both the flexural strength and thermal conductivity increased. In addition, the shrinkage in the Z-direction was higher than that in the X- and Y-directions. Scanning electron microscopy analysis showed that the mean grain size decreased with increasing solid loading. Furthermore, a heat dissipation performance evaluation system was designed to illustrate the heat transmission capacity of AlN ceramics. Simulation and experimental results showed that AIN ceramic parts with complex shapes achieved better heat-dissipation performance than those with simple shapes.