The modeling of ceramics with complex geometric structures currently depends on the handcrafted mode, with long cycles, high costs, and low efficiency; additive manufacturing (AM) technology can solve this problem well. Herein, the porcelain clay paste was successfully prepared for the direct ink writing (DIW) 3D printing process of ceramics with complex geometric structures, and the effects of sodium citrate (SC) content on the rheological properties and DIW 3D printability of the porcelain clay paste were investigated in detail. The SC has a vital role in the rheological behavior of porcelain clay paste. Adding SC increases the absolute zeta potential and decreases the viscosity of the paste, while a high SC content will lead to a low storage modulus of the paste. The porcelain clay paste with an SC content of 0.05% and a paste solid content of 75% possesses suitable rheological properties and a storage modulus for DIW 3D printing. The as-prepared porcelain clay paste has high DIW 3D printability at a pressure of 0.5 MPa, and a 3D-printed green body with a well-densified structure can be achieved. After being sintered, the 3D-printed ceramic exhibits high densification and mechanical properties. A green body with complex geometric structures is quickly and precisely modeled by the DIW 3D printing process with the resultant porcelain clay paste as the raw material. This work provides a practical approach to rapidly fabricating ceramics with complex geometrical structures.

Iron red, a traditional Jingdezhen overglaze color, is primarily colored with iron oxide (Fe₂O₃). In traditional processes, the main ingredient for the iron red overglaze color, raw iron red, is produced by calcining iron vitriol (FeSO₄·7H₂O). Analysis of ancient iron red porcelain samples indicates that the coloration is unstable, ranging from bright red to dark red and occasionally to black. Addressing this, the present study, from a ceramic technology standpoint, conducts a series of calcination experiments on industrial iron vitriol at varying temperatures. Utilizing methodologies such as differential scanning calorimetry-thermogravimetry (DSC-TG), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy with X-ray energy dispersive spectrometry (SEM-EDS), and optical microscopy (OM), this research scientifically explores the impact of iron vitriol’s calcination temperature on the coloration of traditional Jingdezhen iron red overglaze color. The findings indicate that from room temperature to 550 °C, the dehydration of iron vitriol resulted in the formation of Fe₂(SO₄)₃ and a minimal amount of α-Fe₂O₃, rendering the iron red overglaze color a yellowish-red shade. At 650 °C, the coexistence of Fe₂(SO₄)₃ and α-Fe₂O₃ imparted a brick-red color to the iron red. As the temperature was elevated to 700 °C, the desulfurization of Fe₂(SO₄)₃ produced α-Fe₂O₃, transitioning the iron red to an orange red. With further temperature increase to 750 °C, the particle size of α-Fe₂O₃ grew and the crystal reflectivity decreased, resulting in a purplish-red hue. Throughout this stage, the powder remained in a single α-Fe₂O₃ phase. Upon further heating to 800 °C, the crystallinity of α-Fe₂O₃ enhanced, giving the iron red overglaze color a dark red or even black appearance.

This study investigates the identification of artificial irradiation in thermoluminescence (TL) pre-dose dating of ancient Chinese porcelain to address the challenges posed by sophisticated counterfeiting techniques. While TL pre-dose dating is effective for authenticating ceramics, modern imitations artificially irradiated to mimic ancient doses complicate accurate age determination. By analyzing the TL characteristics of five historical porcelain samples (Song, Yuan, Ming, and Qing Dynasties) and artificially irradiated modern replicas, distinct differences were observed. Natural irradiation samples exhibited lower TL sensitivity, less smooth glow curves, and reduced linear regression fit (R² < 0.97) compared to artificial counterparts, which showed higher sensitivity, smoother curves, and superior linearity (R² > 0.97). The following methodology was proposed: annealing samples to erase natural signals, applying equivalent artificial doses, and comparing TL responses. The results demonstrated significant disparities in TL behavior between ancient and irradiated samples, enabling discrimination. This approach enhances the reliability of TL pre-dose dating for porcelain authentication, offering a practical solution to combat forgery in cultural heritage preservation.

The Changsha Kiln of the Tang Dynasty was a major site for celadon production, yet the mechanisms behind the unique coloring of its opaque glazes remain inadequately explored. Prior research has largely focused on the general composition of these glazes, with limited understanding of the specific processes contributing to their distinct visual characteristics. This gap in knowledge hinders efforts to accurately replicate these historical glazes and fully appreciate their technological significance. In this study, we analyze the chemical composition and microstructure of opaque glaze specimens from the Changsha Kiln using advanced techniques such as EDXRF, SEM-EDS, and ultra-deep field microscopy. Our findings reveal that the opaque glazes are high-calcium compositions where phase separation and the presence of coloring ions like Cu²⁺, Cu⁺, and Fe³⁺ play critical roles in determining the glaze’s color. The interplay between chemical coloring and phase separation processes is shown to produce the distinct blue-green and creamy white hues observed in the glazes. These results provide a deeper understanding of the coloring mechanisms in Changsha Kiln glazes, contributing to the broader field of ceramic research and aiding in the preservation and accurate reproduction of these historic artifacts.

The rapid development of archaeology in China has led to the excavation of numerous fragmented porcelain artifacts, for which adhesive materials play a critical role in conservation and restoration. The long-term stability of these adhesives directly affects the structural safety and visual integrity of restored objects. In this study, four adhesives widely used in Chinese conservation practice—epoxy resin Hezhong AAA, epoxy resin Hongxing 509, acrylic resin Paraloid B-72, and cyanoacrylate adhesive 502—were systematically investigated through simulated cyclic aging experiments. A multi-analytical approach was employed, including ultra-depth-of-field microscopy, CIE Lab* colorimetric analysis, pencil hardness testing, and Fourier transform infrared spectroscopy (FTIR). The results reveal distinct aging behaviors among different adhesive types. Epoxy resin adhesives exhibit high initial hardness and pronounced hardening during aging, with coating hardness increasing from the B range to the H range after 15 aging cycles; however, they also show significant yellowing, with total color differences (ΔE) exceeding 10 and dominated by increases in the b* parameter. Paraloid B-72 maintains excellent color stability throughout aging, with ΔE values consistently below 2, although it shows limited thermal stability and delayed physical stabilization. The cyanoacrylate adhesive 502 demonstrates rapid curing and minimal discoloration but undergoes embrittlement and interfacial debonding during aging, indicating reduced long-term bonding reliability. By correlating macroscopic performance evolution with molecular-level chemical changes, this study elucidates the aging mechanisms of commonly used restoration adhesives and provides a scientific basis for adhesive selection, risk assessment, and long–term preservation strategies in porcelain conservation.