JOURNAL OF NUCLEAR MATERIALS
·
2020
·
IF 2.485
Yi Ding,Zhengdi Jiang,Tianheng Xiong,Zimei Bai,Dandan Zhao,Hui Dan,Tao Duan
Zircon is important ceramic used widely due to its excellent properties, in particular for nuclear waste immobilization . However, it is difficult to obtain mono-phase zircon with high yield, usually result in double-phase ZrO 2 /ZrSiO 4 ceramics. Herein, Ce-doped double-phase 0.2Zr 1- x Ce x O 2 /Zr 1- y Ce y SiO 4 (0 ≤ x + y ≤ 1) ceramics were fabricated and their phase and microstructure evolution were studied. The results demonstrated that Ce content has great influence on the phase composition and microstructure. The ceramics with 0 ≤ x + y < 0.1 are tetragonal-ZrSiO 4 , monoclinic-ZrO 2 and tetragonal-ZrO 2 phases, with 0.1 ≤ x + y ≤ 0.3 are tetragonal-ZrSiO 4 , monoclinic-ZrO 2 , tetragonal-ZrO 2 and cubic-ZrO 2 phases, with 0.3 < x + y ≤ 0.6 are tetragonal-ZrSiO 4 , tetragonal-ZrO 2 and cubic-ZrO 2 phases, and with 0.6 < x + y ≤ 1 are cubic-ZrO 2 and Ce 2 Si 2 O 7 phases. With increasing Ce-doping content, the ZrSiO 4 retained the tetragonal phase, while ZrO 2 transformed from monoclinic to stable cubic phase. Furthermore, lattice parameters , grain size and compactness increased with increasing Ce content.
研究领域:
材料科学
·
核废物处理
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Binglu Deng,Hanjin Luo,Zhongqing Jiang,Zhong-Jie Jiang,Meilin Liu
A simple co-polymerization method has been employed to prepare polysilicic-zirconium (PSZr), consisting of chemical species of ZrSi 24 O 50 , ZrSiO 4 , and Zr 5 Si 3 . The obtained PSZr is found to be highly active as the coagulant for the purification of the raw water and humic acid wastewater. The performance of PSZr on the wastewater purification is greatly dependent upon the synthetic temperature of PSZr, and the mole ratio of Si:Zr, and the basicity of the PSZr. It shows that PSZr synthesized at the temperature of 20–25 °C with the mass fraction of polysilicic acid of 1.5%, the mole ratio of Si:Zr of 1:1, and a basicity of 0.25, is relatively more efficient for water purification and could achieve the UV 254 (Ultraviolet wavelength less than 254 nm) and total organic carbon removals of 81.23% and 66.85% and residual turbidity of 0.86 NUT in the raw water, and the UV 254 and TOC removals of 99.20% and 74.21% in simulated humic acid wastewater, respectively. These results clearly demonstrate that PSZr could be used as the coagulant for the wastewater treatments.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2014
·
IF 0
Jian He,Xiao Lei Li,Hui Ming Ji,Qing Pu Wang
ZrO2 wet gel was prepared using zirconium n-butoxide as precursor and 1,2-propylene oxide (PO) as a gelation agent in sol-gel process. Then, tetraethoxysilane (TEOS) was used to strengthen the wet gel in aging process. Finally, the monolithic silica/zirconia aerogel was obtained by supercritical fluid drying. N2 adsorption-desorption method, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize microstructure of the aerogel. The influence of pH of the aging solution on microstructure of silica/zirconia aerogel was studied. The results indicate that the particle size distribution of SiO2/ZrO2 aerogel was more uniform and less aggregate when aging in acid solution. However, the average pore diameter and particle size of SiO2/ZrO2 aerogel was increased by aging in alkaline solution. Aging in alkaline condition was useful for largening the pore size of SiO2/ZrO2 aerogel, and the maximum specific surface area and pore volume were obtained at pH=9. Meanwhile, different reactions were produced between the acid/alkaline solution and the hydroxyl of SiO2/ZrO2 aerogel, and the ester group/amino group was obtained relatively which can modify the network of aerogel and decrease the shrinkage of aerogel during the supercritical fluid drying.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
Journal of Zhejiang University-SCIENCE B
·
2021
·
IF 3.066
Zhiwei SU,Mingxing LI,Ling ZHANG,Chaoyang WANG,Leiqing ZHANG,Jingqiu XU,Baiping FU
Objective To coat a zirconia surface with silica-zirconia using a dip-coating technique and evaluate its effect on resin-zirconia shear bond strength (SBS). Methods A silica-zirconia suspension was prepared and used to coat a zirconia surface using a dip-coating technique. One hundred and eighty-nine zirconia disks were divided into three groups according to their different surface treatments (polishing, sandblasting, and silica-zirconia coating). Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) were used to analyze the differently treated zirconia surfaces. Different primer treatments (Monobond N, Z-PRIME Plus, and no primer) were also applied to the zirconia surfaces. Subsequently, 180 composite resin cylinders (Filtek Z350) were cemented onto the zirconia disks with resin cement (RelyX Ultimate). The SBS was measured after water storage for 24 h or 6 months. The data were analyzed by two-way analysis of variance (ANOVA). Results SEM and EDX showed that the silica-zirconia coating produced a porous layer with additional Si, and XRD showed that only tetragonal zirconia was on the silica-zirconia-coating surface. Compared with the control group, the resin-zirconia SBSs of the sandblasting group and silica-zirconia-coating group were significantly increased ( P <0.05). The silica-zirconia coating followed by the application of Monobond N produced the highest SBS ( P <0.05). Water aging significantly reduced the resin-zirconia SBS ( P <0.05). Conclusions Dip-coating with silica-zirconia might be a feasible way to improve resin-zirconia bonding.
研究领域:
牙科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Dawei Guan,Xianwen Wang,Xiaoyan Chen,Yaozhong Zhang,He Li,Qingxiao Yu,Fei Li
Silica ceramic cores are widely used for forming the inner cavity in hollow turbine blade casting. While the employment of 3D printing brings complex shapes and high production efficiency of ceramic cores, the clear downside of poor properties hinders their practical applications in comparison with traditional ones. This work aims to improve the comprehensive performance of 3D-printed silica ceramic cores, where the proposed powder gradation design leads to silica ceramic cores with high porosity, low shrinkage, and excellent high-temperature flexural strength. DLP-based 3D printing was utilized for ceramic core fabrication here. The studies on the powder shape and size reveal the merits of spherical particles on the flow and irregular particles on the stationarity of ceramic slurry. The sintering process suggests that coarse powder provides sufficient porosity for the core, while medium and fine powder enhance the densification degree of the core. As a result, when the mass ratio of coarse, medium, and fine powders was 1:1:2 and sintered at 1200 ℃, the comprehensive performance of the ceramic core was significantly improved, with a high open porosity of 30 %, reduced shrinkage rate to 1.2 %, surface roughness Ra reduced to 1.25 μm, and the high-temperature flexural strength increased to 39 MPa. This study will provide theoretical guidance and data support for 3D-printed silica ceramic cores.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yongkang Yang,Boran Wang,Jie Li,Jianglin Wang,Ke Wang,Yue Wang,Shuxin Niu,Xin Li,Xiqing Xu
In the vat photopolymerization (VPP) 3D printing of ceramic cores, the solid loading is generally conducive to the microstructure and performance of products, owing to the improved bonding between adjacent layers and enhanced dimensional accuracy with increasing solid loading. In this work, the content of ceramic powder in photosensitive resin was optimized, the solid loading increased from 56 vol% to 68 vol%, and a novel curing model was established to explain the impact of solid loading on the printing precision. During sintering, the shrinkage is regulated to approximately 3 %, demonstrating a more homogeneous structure. The interlayer strength increased to 11.43 MPa while maintaining an apparent porosity of 23.47 %. Furthermore, the anisotropy of VPP-3D printed ceramic cores dependent on the solid loading was investigated. The ratio of vertical strength to horizontal strength (σ V /σ H ) increased from 0.57 to 0.68 when the solid loading grew from 56 vol% to 68 vol%. At 1540 °C, the value of σ V /σ H was further enhanced to 0.81. This value met the precision casting criteria for ceramic cores effectively. This work can provide a reference for the investigation of high-solid-loading ceramic cores.
研究领域:
材料科学
·
制造工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Dawei Guan,Xi Chen,Donghong Wang,Qingxiao Yu,Yaozhong Zhang,Xiaofu Liu,Fei Li
Hollow turbine blades are critical components of aircraft engines, and their performance strongly depends on the dimensional stability and mechanical reliability of ceramic cores during casting. Although most previous studies have focused on the behavior of ceramic cores during the heating and holding stages at casting temperatures, cracks and deformation may also develop during cooling, during which phase transformations can significantly affect the quality of blade castings. In this study, silica ceramic cores with a commercial composition were fabricated by DLP 3D printing, and their phase transformation behavior and evolution of high-temperature mechanical properties during cooling were systematically investigated. SEM and XRD results showed that β-cristobalite gradually transformed into tridymite during cooling. This transformation was accompanied by volume expansion, which compressed cracks and promoted their closure. Correspondingly, the high-temperature flexural strength increased with decreasing temperature and eventually stabilized at 36 ± 0.4 MPa, while the tridymite content exhibited a similar trend and reached 6.5 wt.%. In addition, approximately 0.7–0.9 wt.% of zircon decomposed into zirconia and silica phases at high temperature. These findings demonstrate that the phase transformation and associated microstructural evolution during cooling are closely related to the enhancement of the high-temperature flexural strength of silica ceramic cores.
✓ 已验证
产品关联
DOI
高影响因子
China Foundry
·
2025
·
IF 2.3
Yang Yong-kang,Wang Bo-ran,Jia Zi-qi,Niu Shu-xin,Li Xin,Guo Ya-jie,Xu Xi-qing
Vat photopolymerization (VPP) 3D printing is an optimized technology for complex-shaped ceramic cores, in which the solid loading of ceramic slurries greatly influences the microstructure and property of the final ceramic parts. However, the high solid loading of slurries is highly limited by the high viscosity. In this study, silica-based ceramic core slurries with solid loading up to 68vol.% were achieved by the composition design to optimize the performance, considering the curing, rheological, and double bond conversion rate. The slurries demonstrate superior curing and rheological performance with mass ratio of monomers being 3:2 and mass fraction of BYK111 being 4wt.%. Afterwards, the impact of solid loading on the morphology and mechanical properties was investigated. As the solid loading increases, the microstructure becomes gradually dense, leading to an improved flexural strength of 19.5 MPa. Additionally, the sintering shrinkage becomes more uniform, satisfying the casting requirements effectively. This work serves as a guide for the preparation of ceramic slurries with a high solid loading.
研究领域:
材料科学
·
3D 打印技术
✓ 已验证
产品关联
DOI
高影响因子
Virtual and Physical Prototyping
·
2025
·
IF 8.8
Yongkang Yang,Xiqing Xu,Boran Wang,Shiyuan Li,Ziqi Jia,Xusen Guo,Shuhuai Wang,Shuxin Niu,Xin Li
Vat photopolymerization (VPP) 3D printing technology is suited for intricate ceramic core forming due to its design freedom. However, solving the lateral over-cure width while formation is crucial. Graphene was used in VPP-3D printing of silica-based ceramic cores to examine its effects on forming and sintering, and a desirable curing coefficient was presented to evaluate the forming accuracy of single layer. A straightforward model using a modified Beer–Lambert law based on exposure time rather than exposure power predicts the effect of graphene on the VPP process at consistent curing depth and exposure time and clarifies how the curing process affects flexural strength and surface quality. The optimal graphene content was determined by double bond conversion rate, structural anisotropy, and mechanical properties. Increasing graphene concentration reduces curing sensitivity and exposure time threshold, allowing more liquid phase to cure and improving double bond conversion and interlayer bonding. However, excess graphene increases the conversion rate and stress concentration of green body. According to microstructural studies, extra graphene enhanced the likelihood of crack reformation after sintering. The ceramic cores had optimal forming and sintering capabilities with 0.6 wt.‰ graphene content. The approach offers significant insights for enhancing VPP ceramic 3D printing.
研究领域:
材料科学
·
增材制造
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 5.6
Dandan Yan,Haoqin Yang,Yongkang Yang,Shuxin Niu,Xusen Guo,Xin Li,Xiqing Xu,Zhongde Shan
Ceramic cores serve as critical components shaping the internal hollows within aero-engine turbine blades, and 3D printing excels in producing ceramic cores with complex structures. Herein, silica-based ceramic cores were fabricated via vat photopolymerization 3D printing, and the densification behavior, phase transformation, structure evolution, and anisotropy of the samples was explored based on sintering kinetics analysis. As the sintering temperature rose from 1160 °C to 1200 °C, evident liquid-phase sintering took place, making the microstructure denser. The interlayer fracture mode developed from intergranular to a mixed intergranular-transgranular type, which repaired the interlayer gaps in the ceramic cores and alleviating the anisotropy of the properties. However, as the temperature rose from 1200 °C to 1240 °C, the excess high temperature induced abnormal grain growth, which not only led to the reappearance of inter-layered structures on the sample surface but also generated microcracks within the cores due to the volume change associated with excessive transition from amorphous silica to cristobalite, thereby causing a renewed deterioration of the mechanical properties and anisotropy of the ceramic cores. With sintering temperature of 1200 °C, the ceramic cores demonstrated outstanding comprehensive properties, including a high-temperature deflection of 1.14 mm, room-temperature flexural strengths of 10.77 MPa in vertical direction and 17.53 MPa in horizontal direction. The anisotropy of flexure strength is evaluated by the ratio of strength in vertical direction to that in horizontal direction, and denoted by δV/δH, whose value was 0.71 at room temperature and 0.83 at 1540 °C. This study provides technical guidance for process optimization and anisotropy control of ceramic cores via vat photopolymerization 3D printing.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Faliang Li,Cao Tan,Jianghao Liu,Junkai Wang,Quanli Jia,Haijun Zhang,Shaowei Zhang
Herein, we prepare phase-pure ZrB 2 -SiC composite powders by molten-salt-mediated reduction of ZrSiO 4 /B 2 O 3 /activated carbon mixtures with Mg, showing that the phase composition and morphology of the above composites is influenced by firing temperature, B:Zr and C:Si molar ratios, and the amount of excess Mg. Notably, phase-pure ZrB 2 -SiC powder with a ZrB 2 :SiC weight ratio of ~75:25 could be obtained by 3-h firing at 1200 °C, i.e., at a temperature lower than that used for conventional carbothermal reduction by at least 200 °C. As-prepared ZrB 2 -SiC composites exhibited grain sizes of several microns and comprised SiC nanoparticles well distributed in the ZrB 2 matrix. Finally, the oxidation activation energies of the prepared ZrB 2 and ZrB 2 -SiC powders were determined as 326 and 381 kJ/mol, respectively, which demonstrated that the introduction of SiC improved the oxidation resistance of monolithic ZrB 2 .
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jie Zhang,Kang-Bo Yu,Jia-Min Wu,Chun-Sheng Ye,Wen Zheng,Heng Liu,Shi-Feng Wen,Chun-Ze Yan,Yu-Sheng Shi
SiO 2 -based ceramic cores are widely used in the preparation of gas turbine engine hollow blades due to their excellent chemical stability and easy removal after casting. In this paper, ZrSiO 4 reinforced SiO 2 -based ceramics were fabricated using digital light processing (DLP) technology. The results showed that the addition of ZrSiO 4 reduced the cure depth due to its high UV light absorptivity and refractive index . When the content of ZrSiO 4 increased to 15 wt%, the cristobalite content reached the maximum, and radial shrinkage reached the minimum of 1.4%. ZrSiO 4 grains could hinder the propagation of cracks, enhancing the room-temperature flexural strength . At 1550 °C, fracturing across SiO 2 grains in SiO 2 -based ceramics led to the great improvement of high-temperature flexural strength. When the content of ZrSiO 4 reached 15 wt%, the flexural strength at room temperature and high temperature was 11.5 MPa and 36.7 MPa, respectively. Therefore, the SiO 2 -based ceramics prepared using DLP technology have good room temperature and high temperature properties, and are expected to be used for hollow blade casting.
研究领域:
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）