Additive manufacturing of high-performance aluminium nitride ceramics using high solid loading and low viscosity slurry

Abstract

In this study, the complex aluminium nitride (AlN) components with performance comparable to those produced by conventional methods were fabricated through an improved additive manufacturing technique. The use of a novel surfactant (KMT3331) improved the dispersion of AlN powder in resin, enhancing the compatibility between the powder and the resin, resulting in a low-viscosity slurry with solid loading exceeding 60 vol.%. This approach improved the density and homogeneity of the green bodies, resulting in dense and microstructurally homogeneous AlN ceramics, as well as reduced the sintering shrinkage and grain size. Finally, by controlling oxygen impurities introduced from the debinding process, complex-shaped AlN ceramics with high thermal conductivity (184.56 ± 2.77 W·m−1·K−1), outstanding mechanical properties (bending strength of 458.09 ± 36.03 MPa, fracture toughness of 3.95 ± 0.26 MPa·m1/2) and high reliability (Weibull modulus of 14.89) were obtained, greatly broadening the prospect of AlN ceramics in advanced thermal management applications.

Keywords

• Additive manufacturing
• aluminium nitride
• thermal conductivity
• mechanical properties
• reliability