Precursor-derived ceramic SiOC (PDC-SiOC) microlattices exhibit excellent oxidation resistance, high-temperature stability, and superior mechanical properties. However, the printing accuracy of the PDC-SiOC microlattices by 3D printing is still limited, and mechanical properties of the PDC-SiOC microlattices have not been studied systematically. Here, PDC-SiOC octet microlattices were fabricated by projection micro stereolithography (PμSL) 3D printing, and photoabsorber (Sudan III)’s effect on the accuracy was systematically analyzed. The results showed that the addition of Sudan III improved the printing accuracy significantly. Then, the ceramization process of the green body was analyzed in detail. The order of the green body decreased, and most of their chemical bonds were broken during pyrolysis. After that, the PDC-SiOC microlattices with different truss diameters in the range of 52–220 μm were fabricated, and their mechanical properties were investigated. The PDC-SiOC microlattices with a truss diameter of 52 μm exhibited higher compression strength (31 MPa) than those with bigger truss diameters. The size effect among the PDC-SiOC microlattices was analyzed. Our work provides a deeper insight into the manufacturing of PDC-SiOC micro-scaled architectures by 3D printing and paves a path to the research of the size effect in ceramic structures.

In bone tissue engineering, scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration, attracting increasingly interests in clinical practice. In this study, strontium-incorporated β-tricalcium phosphate (β-TCP), named Sr-TCP, bioceramic triply periodic minimal surface (TPMS) structured scaffolds were successfully fabricated by digital light processing (DLP)-based 3D printing technique, achieving high porosity, enhanced strength, and excellent bioactivity. The Sr-TCP scaffolds were first characterized by element distribution, macrostructure and microstructure, and mechanical properties. Notably, the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%, bringing a great mechanical breakthrough to porous scaffolds. Furthermore, the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line (MC3T3-E1) cells in both gene and protein aspects, verified by alkaline phosphatase (ALP) activity and polymerase chain reaction (PCR) assays. Overall, the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity, boosted strength, and superior bioactivity at the same time, serving as a promising approach for bone regeneration.

Cellular ceramic structures (CCSs) are promising candidates for structural components in aerospace and modern industry because of their extraordinary physical and chemical properties. Herein, the CCSs with different structural parameters, i.e., relative density, layer, size of unit cells, and structural configuration, were designed and prepared by digital light processing (DLP)-based additive manufacturing (AM) technology to investigate their responses under compressive loading systematically. It was demonstrated that as the relative density increased and the size of the unit cells decreased, the mechanical properties of one-layer CCSs increased. The mechanical properties of three-layer CCSs were more outstanding than those of the CCSs with one and two layers. In addition, structural configurations also played a vital role in the mechanical properties of the CCSs. Overall, the mechanical properties of the CCSs from superior to inferior were that with the structural configurations of modified body-centered cubic (MBCC), Octet, SchwarzP, IWP, and body-centered cubic (BCC). Furthermore, structural parameters also had significant impacts on the failure mode of the CCSs under compressive loading. As the relative density increased, the failure mode of the one-layer CCSs changed from parallel–vertical–inclined mode to parallel–vertical mode. It was worth noting that the size of the unit cells did not alter the failure mode. Inclined fracture took a greater proportion in the failure mode of the multi-layer CCSs. But it could be suppressed by the increased relative density. Similarly, the proportions of the parallel–vertical mode and the fracture along a specific plane always changed with the variation of the structural configurations. This study will serve as the base for investigating the mechanical properties of the CCSs.

Silicon carbide (SiC) ceramic and related materials are widely used in various military and engineering fields. The emergence of additive manufacturing (AM) technologies provides a new approach for the fabrication of SiC ceramic products. This article systematically reviews the additive manufacturing technologies of SiC ceramic developed in recent years, including Indirect Additive Manufacturing (Indirect AM) and Direct Additive Manufacturing (Direct AM) technologies. This review also summarizes the key scientific and technological challenges for the additive manufacturing of SiC ceramic, and also forecasts its possible future opportunities. This paper aims to provide a helpful guidance for the additive manufacturing of SiC ceramic and other structural ceramics.

Hydroxyapatite (HA) bioceramic scaffolds were fabricated by using digital light processing (DLP) based additive manufacturing. Key issues on the HA bioceramic scaffolds, including dispersion, DLP fabrication, sintering, mechanical properties, and biocompatibility were discussed in detail. Firstly, the effects of dispersant dosage, solid loading, and sintering temperature were studied. The optimal dispersant dosage, solid loading, and sintering temperature were 2 wt%, 50 vol%, and 1250 ℃, respectively. Then, the mechanical properties and biocompatibility of the HA bioceramic scaffolds were investigated. The DLP-prepared porous HA bioceramic scaffold was found to exhibit excellent mechanical properties and degradation behavior. From this study, DLP technique shows good potential for manufacturing HA bioceramic scaffolds.

In this paper, the rapid cooling thermal shock behaviors of ZrB₂-SiC ceramics were measured using traditional water quenching method, and the rapid heating thermal shock behaviors of ZrB₂-SiC ceramics were investigated using a novel in situ testing method. The measured critical thermal shock temperature difference for rapid cooling thermal shock was 373.6 ℃; however, the critical thermal shock temperature difference for rapid heating thermal shock of ZrB₂-SiC ceramics was measured to be as high as 1497.2 ℃. The thermal stress distribution states after rapid cooling thermal shock and rapid heating thermal shock testing were analyzed using finite element analysis (FEA) method. The FEA results showed that there is a tensile stress existed on the surface for rapid cooling thermal shock, whereas there is a compressive stress existed on the surface for rapid heating thermal shock. The difference of thermal stress distribution resulted in the difference of the critical temperature difference for rapid cooling thermal shock and rapid heating thermal shock.