3D printing (3DP) technologies have transformed the processing of advanced ceramics for small‐scale and custom designs during the past three decades. Simple and complex parts are designed and manufactured using 3DP technologies for structural, piezoelectric, and biomedical applications. Manufacturing simple or complex geometries or one‐of‐a‐kind components without part‐specific tooling saves significant time and creates new applications for advanced ceramic materials. Although development and innovations in 3DP of ceramics are far behind compared with metals or polymers, with the availability of different commercial machines in recent years for 3DP of ceramics, exponential growth is expected in this field in the coming decade. This article details various 3DP technologies for advanced ceramic materials, their advantages and challenges for manufacturing parts for various applications, and perspectives on future directions. We envision this work will be helpful to advanced ceramic researchers in industry and academia who are using different 3DP processes in the coming days.

Melt-grown alumina-based composites are receiving increasing attention due to their potential for aerospace applications; however, the rapid preparation of high-performance components remains a challenge. Herein, a novel route for 3D printing dense (< 99.4%) high-performance melt-grown alumina-mullite/glass composites using directed laser deposition (DLD) is proposed. Key issues on the composites, including phase composition, microstructure formation/evolution, densification, and mechanical properties, are systematically investigated. The toughening and strengthening mechanisms are analyzed using classical fracture mechanics, Griffith strength theory, and solid/glass interface infiltration theory. It is demonstrated that the composites are composed of corundum, mullite, and glass, or corundum and glass. With the increase of alumina content in the initial powder, corundum grains gradually evolve from near-equiaxed dendrite to columnar dendrite and cellular structures due to the weakening of constitutional undercooling and small nucleation undercooling. The microhardness and fracture toughness are the highest at 92.5 mol% alumina, with 18.39±0.38 GPa and 3.07±0.13 MPa·m^1/2, respectively. The maximum strength is 310.1±36.5 MPa at 95 mol% alumina. Strength enhancement is attributed to the improved densification due to the trace silica doping and the relief of residual stresses. The method unravels the potential of preparing dense high-performance melt-grown alumina-based composites by the DLD technology.

Al₂O₃/Al₆Ti₂O₁₃ composite ceramics with low thermal expansion properties are promising for the rapid preparation of large-scale and complex components by directed energy deposition-laser based (DED-LB) technology. However, the wider application of DED-LB technology is limited due to the inadequate understanding of process conditions. The shaping quality, microstructure, and mechanical properties of Al₂O₃/Al₆Ti₂O₁₃ (6 mol% TiO₂) composite ceramics were systematically investigated as a function of energy input in an extensive process window. On this basis, the formation mechanism of solidification defects and the evolution process of microstructure were revealed, and the optimized process parameters were determined. Results show that high energy input improves the fluidity of the molten pool and promotes the uniform distribution and full growth of constituent phases, thus, facilitating the elimination of solidification defects, such as pores and strip gaps. In addition, the microstructure size is strongly dependent on the energy input, increasing when the energy input increases. Moreover, the morphology of the α-Al₂O₃ phase gradually transforms from cellular into cellular dendrite with increasing energy input due to changing solidification conditions. Under the comprehensive influence of solidification defects and microstructure size, the fracture toughness and flexural strength of Al₂O₃/Al₆Ti₂O₁₃ composite ceramics present a parabolic law behavior as the energy input increases. Optimal shaping quality and excellent mechanical properties are achieved at an energy input range of 0.36−0.54 W*min² g⁻¹ mm⁻¹. Within this process window, the average microhardness, fracture toughness, and flexural strength of Al₂O₃/Al₆Ti₂O₁₃ composite ceramics are up to 1640 Hv, 3.87 MPa m^1/2, and 227 MPa, respectively. This study provides practical guidance for determining the process parameters of DED-LB of melt growth Al₂O₃/Al₆Ti₂O₁₃ composite ceramics.

Al₂O₃-based composite ceramics have excellent high temperature performance and are ideal materials for preparing hot end components. However, poor fracture toughness and thermal shock resistance limit its applications. Based on the excellent low thermal expansion characteristics and thermal shock resistance of Al₂TiO₅ ceramic, different composition ratios of Al₂O₃/Al₂TiO₅ composite ceramics were prepared by directed laser deposition (DLD) technology. Effects of TiO₂ doping amount on microstructure and properties of the composite ceramics were investigated. Results show that α-Al₂O₃ phase is discretely distributed in the continuous aluminum titanate matrix when TiO₂ doping amount between 2 and 30 mol%. With the increase of TiO₂ doping amount, content of Al₂O₃ gradually decreases and its morphology changes from cellular to dendritic. When TiO₂ doping amount reaches 43.9 mol%, the microstructure transforms into fine Al₂TiO₅/Al₆Ti₂O₁₃ eutectic structure. Property test results show that Al₂O₃/Al₂TiO₅ composite ceramics have good comprehensive mechanical properties when TiO₂ doping amount between 2 and 6 mol%.