Table of Content

15 May 2024, Volume 43 Issue 5

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Special Issue on 3D Printing Technology for Inorganic Non-Metallic Materials (II)

A Fundamental Study Progress on Reinforcement Enhancement of 3D Printed Concrete

XIAO Jianzhuang, LYU Zhenyuan, LIU Haoran

2024, 43(5):  1545-1556. 

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3D printed concrete (3DPC) has been the subject of ongoing study in recent years due to the growing trend of intelligent building materials industry and construction industry. Due to the automation, intelligent, and formwork-free advantages, several engineering demonstrations have been established. There are more demands on 3DPC properties because of its widespread application in engineering. Engineering applications are also placing greater demands on the performance of 3DPC which requiring selective reinforcement enhancements for safe and reliability design. 3DPC reinforcement technology is different from casting concrete construction due to the changing preparation process. And scientific optimization and performance control should be carried out for the reinforcement method under printing. This paper focuses on the development of 3DPC reinforcement enhancement study in terms of the reinforcing process, materials and features, numerical analysis, and comprehensive microscopic characterization. In addition, the challenges faced by reinforcement enhancement fundamental research and the technical difficulties of future development are also briefly discussed. The intention is to serve as a reference for the scientific development of reinforced 3DPC structures, meeting the demand for safe applications guidance.

Study Progress on Reinforcement Technology for 3D Printing Concrete

MAO Yufei, GUO Zenghui, CHEN Hui, ZHANG Jie, LUO Jianlin, LIU Chao, SHANG Huaishuai

2024, 43(5):  1557-1568. 

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3D printing technology has disrupted the traditional manufacturing process, which covers widespread applications across various sectors, including aerospace, automotive, medical, construction and cultural innovation engineering. The sources of concrete raw materials are wide and low in cost, having good placeability, and widely used in civil infrastructure. In the context of modern information and automation, 3D printing technology combined with concrete produces 3D printing concrete (3DPC) can not only effectively save raw materials and environmentally friendly construction, but also enable more flexible construction of various types of assembled structures with high automation. However, 3DPC still has many limitations, such as low tensile strength, inferior earthquake resistance, reinforcement problems and low inter-layer bonding strength, etc. Various reinforcement techniques need to be developed to improve performance. Here, this paper focuses on the impact of various reinforcing techniques involving steel bar reinforcement, fiber reinforcement, and other reinforcement methods, on the performances of 3DPC, and expounds the possible problems and future development trends.

Current Research Status and Prospects of 3D Printing Glass Materials

YANG Chenqian, LIU Chao, CHEN Peng, LIU Kai

2024, 43(5):  1569-1587. 

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As an amorphous material with high optical transparency, high thermal and chemical stability, high melting point and low coefficient of thermal expansion, glass is widely used in optics, biology, medicine and other fields. With the increasingly high requirements for the structure, material distribution and functional properties, traditional glass material processing methods (such as casting, blowing, floating, etc.) are difficult or even impossible to meet the above requirements. The emergence of 3D printing technology has subverted the traditional material forming process, which is based on the manufacturing principle of layer-by-layer accumulation, and theoretically can realize the digital forming of any complex components, with no molds, forming efficiency and other advantages. 3D printing technology has been widely concerned by the scholars in the field of glass material forming and manufacturing. This review systematically summarizes the 3D printing processes, principles, and their advantages and disadvantages for glass materials. Discussions are then presented on the applications of 3D printing glass materials. Finally, the future development is presented for the 3D printing technology of glass materials.

Research Progress of Stereolithography 3D Printing of Silicon Nitride Ceramics

ZHOU Qingxuan, WANG Yang, HAN Zhuoqun, ZHAO Zhicheng, CHU Wei, ZHAO Jie, LIU Jia, WANG Yingying, CHENG Zhiqiang, LI Ling, LIU Futian

2024, 43(5):  1588-1599. 

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Compared to other additive manufacturing techniques, stereolithography 3D printing exhibits unique advantages in fabricating ceramics with complex structures, high density, and superior surface accuracy, thus emerging as a focal point in ceramic additive manufacturing research. However, the high refractive index and strong light absorption properties of silicon nitride ceramics pose challenges in photopolymerization processes, hampering their development and application. This paper analyzes the rheological behavior and curing characteristics of silicon nitride ceramic slurries, and summarizes the challenges encountered in their rheological and curing properties. Furthermore, it consolidates research efforts aimed at enhancing the photopolymerization performance of silicon nitride ceramic slurries and discusses several approaches such as powder modification and resin composition regulation. Finally, detailed insights are provided into the future trends and directions of silicon nitride ceramics stereolithography 3D printing.

Research Progress of Ceramic 3D Printing Technology

YANG Yan'an, LI He, MU Baoxia

2024, 43(5):  1600-1614. 

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3D printing technology is widely used in aerospace, automotive, medical, weapons and other fields because of its advantages of high processing accuracy, low cost, easy operation and flexible manufacturing. Combining 3D printing technology with ceramic molding manufacturing can solve many problems caused by the use of traditional ceramic manufacturing technology. 3D printing technology mainly includes ink-jet printing technology, direct ink writing molding technology, stereolithography molding technology, fused deposition of ceramic molding technology, and selective laser sintering molding technology. In this paper, the characteristics and research progress of each 3D printing technology are summarized, the ceramic slurry preparation and post-processing process in the light-curing molding technology are expounded, the application of finite element numerical simulation in the field of 3D ceramic printing technology is discussed, the characteristics and application status of silicon oxide, silicon carbide, alumina, zirconia, ceramic precursor, and tricalcium phosphate ceramic are analyzed, and finally the current problems and future development potential of ceramic 3D printing technology are summarized.

Study on Printability of Mortar for 3D Printing

LI Fei, LU Ya, LI Weihan, XU Xiaoming, ZHOU Huajie, ZHANG Zheng, ZHOU Li'an

2024, 43(5):  1615-1622. 

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Observational methods are widely used to assess the printing performance of 3D printing materials in current research and technical standards, lacking of quantitative evaluation for extrudability and constructability. In this paper, based on the influences of conventional working performance indicators such as fluidity on printability, two quantitative indicators of extrusion uniformity and cumulative deformation rate were proposed to evaluate the printability of 3D printing materials, and the relationship between conventional working performance indicators and printing quality was established under experimental conditions. The results show that the extrusion uniformity of 3D printing mortar increases first and then decreases with the increase of fluidity, and decreases with the increase of dynamic yield stress. The cumulative deformation rate decreases with the increase of height retention rate and decreases with the increase of static yield stress. Under the conditions of this test parameters, when the extrusion uniformity is less than 3.5%, the cumulative deformation rate is not more than 6%, the dynamic yield stress is 200～800 Pa, and the static yield stress is 1 800～3 300 Pa, the number of printing layers of mortar is higher (not less than 30 layers), and the printability is better.

Research on Rheological Properties, Printability and Mechanical Properties of 3D Printing Coal Gangue Mortar

PENG Shaobin, GUAN Xuemao

2024, 43(5):  1623-1632. 

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To expand the application scope of coal gangue. In this study, gangue aggregate is used to partially or completely replace (mass fraction of 0%, 50% and 100%) nutural sand in 3D printing mortar, and the effect of gangue aggregate addition on the the rheological model, rheological properties, printability, and mechanical properties of 3D printing mortar was systematically examined. The results reveal that, the addition of coal gangue reduces the mechanical properties of 3D printing mortar, but when the coal gangue content is 100%, the compressive strength at 28 d still exceeds 30 MPa, meeting the requirements for mechanical properties. The rheological properties of 3D printing mortar mixed with gangue aggregate conform to the modified Bingham model. Both static yield stress and dynamic yield stress increase proportionally with higher gangue doping. Notably, when the gangue doping is 100%, the growth rate of time-dependent static yield stress is fast, while the growth rates of time-dependent flowability and time-dependent dynamic yield stress are slow. This indicates that the introduction of gangue significantly improves the printability of 3D printing mortar.

Bond Performance Between Embedded Rebar and 3D Printed Mortar

ZHOU Xun, LIU Genjin, WANG Yinhui, LI Hedong, GENG Jian, XIE Weihong, NI Kun

2024, 43(5):  1633-1641. 

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In order to explore the feasibility of rebar embedding technology in 3D printed cement-based materials, this study conducted a series of pull out tests to investigate the influence of rebar embedding methods (pre-embedded, embedded), forming methods (pouring, printing), the angle between the printing bar and the rebar (0°, 90°), and bond length (5Ø, 7Ø, 10Ø, Ø is rebar diameter) on the bond performance between embedded rebar and 3D printed mortar. Comparative analysis was carried out on the ultimate load, relative slip between rebar and mortar matrix, and failure modes of different specimens. The results show that when the printing bar is perpendicular to the rebar, the best bonding effect is achieved using the rebar embedding method. The ultimate load of vertically printed embedded rebar specimens is 58.30% higher than that of pre-embedded rebar specimens. Under the rebar embedding method, the corresponding slip value of the ultimate load increases. Additionally, with the increase of the bond length, the ultimate load increases, but the increase becomes less significant when the bond length exceeds 7Ø, and the failure mode changes from splitting failure to rebar pullout. The study indicates that reinforcement with rebar embedding can significantly improve the bond performance between 3D printed mortar and rebar and enhance the deformation capacity of the specimens.

Effects of Different Inorganic Thickeners on Properties of 3D Printed Cement-Based Materials

MA Xiaoyao, JIAN Shouwei, LI Baodong, HUANG Jianxiang, GAO Xin, XUE Wenhao, WANG Caifeng

2024, 43(5):  1642-1650. 

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The working performance of 3D printed cement-based materials is a decisive factor affecting their final state. The existing technology mostly uses organic thickeners to regulate its working performance, but there are problems such as reduced strength and high cost. This article selected three inorganic thickeners, namely attapulgite, diatomaceous earth, and sodium based bentonite, to study and compare the working performance and mechanical properties of 3D printed cement-based materials under different thickener dosages. The results show that the working performance of 3D printed cement-based materials improves with the increase of inorganic thickener dosage. The optimal dosage of attapulgite and diatomaceous earth is 2.5% (mass fraction), and the optimal dosage of sodium based bentonite is 1.0% (mass fraction). Among them, sodium based bentonite has the best improvement effect. Different inorganic thickeners also have different effects on the mechanical properties of 3D printed cement-based materials. High dosage of attapulgite has no adverse effect on the strength of 3D printed cement-based materials, diatomaceous earth can enhance the later strength of 3D printed cement-based materials, a small amount of sodium based bentonite can significantly improve the overall strength of 3D printed cement-based materials. The 3D printed cement-based material mixed with 1.0% sodium based bentonite has the best comprehensive performance.

Anisotropic of 3D Printed Cement-Based Materials Reinforced with Metakaolin and Limestone Powder

ZHANG Zhaorui, LUO Surong, LIN Xin

2024, 43(5):  1651-1662. 

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3D printed cement-based materials decreases interstrip contact surface properties due to the stack molding process. Metakaolin can reduce porosity and improve mechanical property, but its high water demand cause water loss on the surface of printing strip, and the interlayer bonding performance decline. Limestone powder has a dilution effect, which can improve the high water demand of metakaolin. The influences of metakaolin and mixed limestone powder on anisotropic performance of 3D printed cement-based materials were studied, and the mechanism from a microscopic perspective was explained. The results show that the optimal mass content of metakaolin is 12%, and the optimal mixing mass ratio is m(metakaolin) ∶m(limestone powder) is 2 ∶1. After adding metakaolin, the fluidity of 3D printed cement-based materials decreases significantly, the fluidity of mixed limestone powder increases. The compressive strength of 3D printed test block is characterized by X>Z>Y>molding, and the variation pattern of flexural strength in different directions is basically the same as the compressive strength, with anisotropic characteristics.

3D Printing Performance of Metakaolin Modified Light Burnt Magnesia-Based Magnesium Phosphate Cement

LI Nan, ZHONG Jianjun, DENG Yongjie, LIANG Yun, WAN Detian, LI Weihong, LI Dongwei

2024, 43(5):  1663-1672. 

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In this paper, the 3D printing light burned magnesia-based magnesium phosphate cement material was realized by using the self-developed integrated building 3D printing equipment with mixed stirring and extrusion function. The effect of different metakaolin (MK) content on the properties of 3D printing light burned magnesia-based magnesium phosphate cement was investigated, and combined with XRD and SEM test to further analyze the influence of MK content on the hydration products and crystal appearance of light burnt magnesia-based magnesium phosphate cement. The results show that the setting time and mechanical properties of 3D printing light burnt magnesia-based magnesium phosphate cement increase first and then decrease with the increase of MK content. When MK replaces 4% to 6% of the total mass of magnesia and potassium dihydrogen phosphate, the addition of MK effectively improves the printing performance of light burnt magnesia-based magnesium phosphate cement paste. At this time, the light burned magnesia-based magnesium phosphate cement has good extrusion performance, construction performance and mechanical properties, which can meet the application requirements of 3D printing. The addition of MK does not change the crystal composition of the hydration products of light burnt magnesia-based magnesium phosphate cement, but produces a large number of amorphous amorphous hydration products, which can further fill the gap between hydration products and particles and improve the compactness of structure.

Effect of Fly Ash on Water Resistance of Powder Bed 3D Printing Magnesium Phosphate Cement-Based Materials

LIU Xiaojiang, LI Zhijian

2024, 43(5):  1673-1682. 

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Magnesium phosphate cement-based material has the characteristics of fast hardening and early strength, which is suitable for cement-based powder bed 3D printing technology. In order to solve the problem of poor water resistance of powder bed 3D printing magnesium phosphate cement, the optimization of water resistance of powder bed 3D printing magnesium phosphate cement-based materials was carried out. The influence of M/P molar ratio on water resistance of materials was studied, and M/P molar ratio was optimized. The effect of fly ash incorporation on the printing performance and water resistance of powder bed 3D printing magnesium phosphate cement-based materials was studied, and the mechanism of fly ash improvement on water resistance of printing materials was revealed by combining the microscopic characterization methods. The results show that the compressive strength of powder bed 3D printing magnesium phosphate cement-based materials decreases under water curing condition. With the increase of M/P molar ratio, the water resistance of specimen is improved accordingly. The addition of fly ash can effectively improve the density and printing accuracy of the powder bed, increase the amount of hydration products, make the microstructure more dense, and improve the water resistance of specimen. By adding 20% (mass fration) fly ash, the compressive strength of materials increases by 89.00% at most after 28 d of water immersion, which provides strong support for improving the water resistance of powder bed 3D printing magnesium phosphate cement-based materials and expanding the application of cement-based powder 3D printing technology.

Effect of Attapulgite Clay on Working Performance and Compressive Strength of 3D Printed Cementitious Materials

WU Chunqun, HAN Kang, LI Denghui, YANG Huashan

2024, 43(5):  1683-1693. 

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The application of high-volume fly ash in 3D printing concrete has the problem of reduced performance such as buildability and compressive strength. In order to improve this problem, attapulgite was used as an admixture in this paper. The effect of attapulgite clay (ATP) content (0%, 1%, 2% and 3%, mass fraction) on the working performance and compressive strength of high-volume fly ash 3D printing cement-based materials was studied. The results show that ATP adsorbs a large amount of water in slurry and fills the voids of larger cement particles, which reduces the fluidity of slurry and increases the strength and yield stress of slurry. When the content of ATP is 1%~3%, the extrudability and buildability of sample are good. With the increase of ATP content, the compressive strength of the printed test block curing for 7 and 70 d in X, Y and Z directions is higher than that of control group. When the curing time is 7 d, the compressive strength of sample with 3% ATP in Z direction is the largest, which is 14.0 MPa. When the curing time is 70 d, the compressive strength of sample with 2% ATP in Y direction is the largest, reaching 24.1 MPa.

Mechanical Properties of 3D Printed Concrete Reinforced by Embedding Multi-Cables

LUO Shu, LI Zhijian, WANG Li

2024, 43(5):  1694-1703. 

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The synchronous strengthening method of continuous micro-cable meets the flexibility requirements of 3D printing technology of concrete and can effectively improve the strength and ductility of 3D printed concrete structures. To further improve the bearing capacity of 3D printed concrete structures, a synchronous multi-cables reinforcement method of 3D printed concrete was proposed. Optimizing the multi-cables synchronous embedding process, pull-out tests were carried out to study the bonding characteristics between multi-cables and matrix material. Four-point bending tests were carried out study the effect of reinforcement ratio on the bending performance, and the formula for calculating normal section capacity and oblique section capacity of multi-cables reinforced 3D printed concrete beams was established. The results show that the pull-out of micro-cable damages the matrix material, then reduces the bonding strength between the remaining micro-cables and the matrix material, and decreasing range increases with the decrease of the micro-cables spacing. The maximum decrease is 43.7% when the micro-cable spacing decreases to 4 mm. When the reinforcement ratio of specimen increases from 0.17% to 0.75%, the ultimate bearing capacity of specimen increases by 220.0% under bending load. The established calculation formula has good accuracy for predicting the normal section capacity and oblique section capacity of multi-cables reinforced 3D printed concrete beams.

Anisotropy and Cause Analysis of Carbonation Resistance of 3D Printed Concrete

WANG Hailong, HOU Jianhua, SUN Xiaoyan, LIN Xiqiang, LU Lan

2024, 43(5):  1704-1712. 

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Attributed to extrusion technology, there are many interfaces in 3D printed concrete, such as interlayer and interstrip interfaces, which affect the durability of printed concrete. In order to investigate the effect of printed interfaces and water binder ratio on the carbonation resistance of 3D printed concrete, the carbonation behavior of 3D printed concrete with three water binder ratios along X, Y, and Z directions was studied through carbonation tests. Based on mercury intrusion testing and X-CT scanning, the pore characteristics and distribution patterns in 3D printed concrete were obtained, and the change mechanism of carbonation resistance of 3D printed concrete was explained from a microscopic level. The research results indicate that pores are closely related to the carbonation behavior of 3D printed concrete. The interstrip and interlayer interfaces generate more pores due to the stacking of stripes, resulting in faster diffusion of CO₂ and greater carbonation depth at these two positions. Therefore, the carbonation resistance of printed concrete exhibits significant anisotropy due to the influences of interfaces. The carbonization resistance of matrix material is better than that of interlayer position and the carbonization resistance of interlayer position is better than that of interstrip position. The lower the water binder ratio is, the better the carbonization resistance of material is. When CO₂ diffuses in concrete, the uncarbonized islands are formed in printed concrete due to the effect of large pores between layers.

Numerical Analysis of 3DPC Interface Machanical Performance and Its Influence on Material Elastic Constants

CHEN Zhaohui, GERONG Wangdui, WANG Pengfei, ZHANG Xiaoyue, ZHANG Zhigang, LIAO Minmao

2024, 43(5):  1713-1722. 

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A numerical simulation method for anisotropy of 3D printed concrete (3DPC) based on interface model was proposed by applying micromechanics theory of composite materials. This method quantitatively revealed the mechanical behavior of layer/filament interface and its influence on anisotropic elastic constants of 3DPC. By combining interface elements and continuum elements, the interface sliding-cracking behavior and mechanical properties of printed filament were simulated. Uniaxial compression, splitting tension, cross-bonded tension, and inclined shear tests were designed to determine the parameters and corresponding ranges required for model. The research shows that the interface tensile and shear traction-separation curves exhibit a bilinear characteristic, and the strength of filament interface is generally higher than that of layer interface. There is no significant difference in shear behavior in two shear principal directions. The elastic modulus between filament and layer has a linear impact on overall elastic modulus and has an exponential impact on Poisson’s ratio. The shear modulus between filament and layer has a comprehensive impact on overall shear modulus.

Research on Mechanical Properties and Compressive Strength Prediction of Steam-Cured 3D Concrete Printing Based on Deep Learning

SUN Junbo, WANG Yufei, ZHAO Hongyu, WANG Xiangyu

2024, 43(5):  1723-1738. 

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3D concrete printing (3DCP) technology has garnered extensive attention in recent years. However, few investigations focus on the effect of curing conditions on the mechanical properties of 3DCP. This study primarily investigated the influences of different steam curing conditions (temperature rise rate, sustained temperature time and sustained temperature) on the mechanical performance of 3DCP at various curing ages. To identify optimal steam curing conditions, an orthogonal experiment was conducted to study the mechanical anisotropy of printed cementitious material. Moreover, based on laboratory test data, a conditional tabular generative adversarial network (CTGAN) was established for data set augmentation, expanding from 291 to 1 000 data entries. A one-dimensional residual convolutional neural network (1D-Residual CNN) was developed to predict the compressive strength of 3DCP, accompanied by five machine learning (ML) models for comparison. Experimental results indicate that CTGAN's data augmentation technique significantly enhanced the predictive accuracy of the 1D-Residual CNN model on the compressive strength of 3DCP, with the highest R² reaching 0.92.

Digital Design and Construction of Medium and Small Span Concrete 3D Printed Box Arch Bridge

BAI Songlin, GAO Yimin, ZHAO Ziqiao, ZHANG Ning, LI Gang, LIU Shilong, YANG Min

2024, 43(5):  1739-1747. 

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This paper introduces the structural composition and construction method of the concrete 3D printed landscape arch bridge in Xi’an Archaeological Park, and elaborates on the core design elements of arch bridge. Referring to the traditional Chinese decorative pattern “Thunder Cloud Pattern”, a unique arch bridge appearance was printed through the path planning technology for concrete 3D printing. Based on the stress characteristics of the superstructure and considering the application range of concrete 3D printing system, the arch bridge was optimized and divided into blocks. In order to meet the structural design requirements, the printing materials were specially processed to complete the construction of arch bridge superstructure. Simulation analysis was conducted on the arch bridge using ANSYS software to examine its structural strength and dynamic characteristics. The calculation results indicate that the performance parameters of arch bridge meet the design requirements. In the end, this paper elaborates on the construction technology of concrete 3D printed box arch bridge, including arch bridge printed component assembly and overall installation.

Influence of Attapulgite Clay on Basic Properties and Printability of Gypsum 3D Printing Materials

WANG Caifeng, JIAN Shouwei, LI Baodong, HUANG Jianxiang, GAO Xin, MA Xiaoyao, XUE Wenhao

2024, 43(5):  1748-1755. 

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Thickener is a crucial component in 3D printing materials. However, commonly used thickeners are predominantly organic matter, leading to a reduction in the mechanical performance of gypsum. In order to solve this issue, attapulgite clay and hydroxypropyl methylcellulose ether were compared to test their effects on the workability performance, mechanical performance, and printability of gypsum 3D printing materials. The results show that, attapulgite clay reduces the fluidity of gypsum 3D printing materials and increases dynamic yield stress, similar to hydroxypropyl methyl cellulose ether. The flexural and compressive strength of the material decreases first and then increases as the attapulgite clay content increases, while the flexural and compressive strength of the hydroxypropyl methylcellulose ether group shows a declining trend. In the actual 3D printing process, the volume stability and open time results of attapulgite clay groups are similar to those of the hydroxypropyl methylcellulose ether groups, but the actual printing strength is more than 23% higher than that of the hydroxypropyl methylcellulose ether groups. Hydroxypropyl methylcellulose ether achieves viscosity enhancement by water absorption and molecular entanglement, whereas attapulgite clay, with its abundant pore structure, thickens the slurry by adsorbing water molecules and gypsum particles through hydrogen bonding and Van der Waals forces.

Study on 3D Printing Flexible SiO₂ Aerogel Composites

CHEN Hao, CHU Chengyi, WANG Yuting, BAO Xixi, QIU Zhuohao, CHENG Yuchuan, GUO Jianjun, SHAN Xinggang, SUN Aihua

2024, 43(5):  1756-1763. 

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SiO₂ aerogel is an excellent thermal insulation material, which has excellent properties, due to its special network structure, such as high specific surface area, high porosity, low thermal conductivity and low density. However, the mechanical properties of SiO₂ aerogel are fragile, which makes it difficult to prepare complex and miniature components by traditional manufacturing methods, which greatly hinders the development and application of SiO₂ aerogel in the field of heat insulation. In this paper, flexible SiO₂ aerogel composites were prepared by 3D printing direct writing technology. By studying the content of different polyvinyl alcohol solutions and sodium stearate, the optimal slurry ratio was found. The thermal conductivity of the printed flexible SiO₂ aerogel composites at 100 ℃ is as low as 0.026 W/(m·K), and it has good compression performance, bending performance and hydrophobicity. This study provides a possibility for the large-scale application of SiO₂ aerogel.

Preparation of High-Performance BaTiO₃ Piezoelectric Ceramics by Stereolithography 3D Printing

BI Lunan, LI Ling, SONG Tao, WANG Yingying, LYU Jiaqi, LU Xiang, HAN Zhuoqun, WANG Yang

2024, 43(5):  1764-1771. 

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Stereolithography 3D printing technology has broad application prospects in the preparation of special-shaped piezoelectric ceramics. In this paper, barium titanate (BaTiO₃) piezoelectric ceramics were prepared by digital light processing technology. The effects of green body morphology and sintering temperature on the microstructure of barium titanate were studied. The results show that the introduction of Triton X-100 makes the viscosity of ceramic slurry less than 3 Pa·s, and the introduction of ceramic powder does not change the properties of resin. The bonding between the layers of ceramic green body is good, and there are no obvious defects. The BaTiO₃ ceramics after sintering contains tetragonal and orthorhombic phases. The remanent polarization is 27.6 μC/cm², the coercive field is 4.6 kV/cm, the relative dielectric constant is 2 512, the dielectric loss is 0.009 1, the Curie temperature is 167 ℃, and the dielectric constant is 182 pC/N.

High-Temperature Sintering and Polarization Process of Additive Manufacturing Barium Titanate Piezoelectric Ceramics

LIU Kai, LU Chao, HE Junchao, LI Tianyang, SHEN Chunhua, YAN Chunze, SHI Yusheng, SUN Huajun

2024, 43(5):  1772-1783. 

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In order to improve the comprehensive performance of BaTiO₃ piezoelectric ceramics fabricated by additive manufacturing, the slurry shear thinning characteristics and digital light processing (DLP) forming characteristics of BaTiO₃ piezoelectric ceramics were studied in this paper. The densification mechanism of BaTiO₃ piezoelectric ceramics green body formed by DLP under different sintering temperature conditions was revealed, and the influence of polarization direction on the piezoelectric properties of BaTiO₃ ceramics formed by DLP was explored. The results show that the electrical properties of BaTiO₃ piezoelectric ceramics fabricated by DLP additive manufacturing can be improved to a certain extent by adjusting the high temperature sintering and polarization process. When the sintering temperature is 1 420 ℃ and the holding time is 2 h, the piezoelectric coefficient d₃₃ is the largest, which is 163.4 pC/N. The sample layers are tightly bonded and the grain size is uniform. When the angle between Z axis and polarization direction is changed from 0° to 90°, the relative dielectric constant ε_r and d₃₃ are increased by 29.37 % and 27.01 %, respectively. When the solid content is 80% (mass fraction), the sintering temperature is 1 420 ℃, and the angle between Z axis and polarization direction is 90°, the sample d₃₃ is the largest, reaching 182.4 pC/N.

Structure Optimal Design of Fusion TPMS Alumina Ceramic Scaffold Prepared by SLA Printing

XUE Wei, DONG Tianyuan, HUANG Chen, HOU Zhishan, CAO Yu, WEI Xinlei

2024, 43(5):  1784-1795. 

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The three-cycle minimum surface (TPMS) structure has excellent mechanical and biomedical properties. By designing and manufacturing suitable TPMS bone scaffold structure, it provides the possibility for the clinical treatment of bone repair, bone replacement and bone healing. Based on the structure parameters of human bone tissue, TPMS scaffolds with three main types of P, G and D and the fusion TPMS scaffolds with different fusion coefficient K values were designed respectively. The ceramic billets were prepared by UV stereophotolithography (SLA), and the molded alumina ceramic scaffolds were obtained through degrease and post-sintering treatment. The results show that: 1) the ceramic bracket has a relatively smooth surface and high molding accuracy, and its overall shape is basically consistent with the design model, and the side surface is slightly rougher than the top surface. 2) Compared with the single-type structure, the fused TPMS structure shows better compressive strength and stress distribution. When the fusion coefficient K=4, the mechanical properties of the P and G fusion scaffold are the best, the compressive strength is 71.72 MPa, and the maximum stress and average stress are 141.90 and 13.214 MPa, respectively. 3) The permeability of fusion structures is weaker than that of single-type structures, and the permeability of scaffolds with different fusion coefficient K values is also different. Combined with numerical simulation and experimental data, when the fusion coefficient K=1 or 2, the permeability of scaffolds with P and G structures and P and D structures is better. In conclusion, when the fusion coefficient K=1, the fusion scaffold with P and G structure has better mechanical properties and permeability, so it is suitable for the structure type of human bone scaffold.

Cement and Concrete

Research Progress in Dispersion Technology and Characterization Methods of Carbon Nanomaterials in Cementitious Materials

LI Yuyang, ZHAO Lige, LIU Shuang, HAN Kang, LIU Yanjun, LI Runfeng, ZHENG Yongchao

2024, 43(5):  1796-1811. 

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Carbon nanomaterials have received extensive research and attention because of unique structure and excellent performance to be used as reinforcing materials to improve the performance of cementitious materials. However, the enhancement effect is based on the good dispersion of carbon nanomaterials in the cement. The large specific surface area and strong intermolecular forces of carbon nanomaterials make them difficult to be dispersed in the cement matrix, and the dispersion effect is difficult to judge. This paper systematically sorts out the mechanism of common carbon nanomaterials agglomeration in cementitious materials, summarizes the dispersion techniques adopted by scholars in recent years, analyses the mechanism, advantages and disadvantages of various dispersion methods in detail, and lists the characterization methods for the dipersion effect of carbon nanomaterials in cementitious material. In the future, the research should focus on the development of more efficient and suitable dispersion methods for industrialized production, and the means of evaluating the real dispersion state of carbon nanomaterials in the cement matrix, which can facilitate the scale-up of nanocarbon-modified cementitious composites for application in real engineering projects.

Properties of Multi-Component Composite Cementitious System of Regenerated Micropowder

PEI Junjun, YUAN Bowen, GAO Min, GUO Qilong, LIN Zhenghong, HEI Yameng

2024, 43(5):  1812-1821. 

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Composite cementitious system of regenerated micropowder is beneficial for the application of regenerated micropowder. A binary/ternary cementitious composite system was constructed by using regenerated micropowder-Portland cement-fly ash. The effect of regenerated micropowder content on physical and mechanical properties of mortar test block was studied, and the hydration products and microstructure of mortar test block were investigated by XRD and SEM. The results show that with the increase of regenerated micropowder content, the compressive strength of test block at 3, 7 and 28 d decreases, the water demand increases, the fluidity decreases, and the dry shrinkage decreases first and then increases. The drying shrinkage of composite cementitious system mortar test block mixed with regenerated micropowder and fly ash developes rapidly within 7～14 d. With the increase of regenerated micropowder and fly ash content, formation of C-S-H decreases gradually, and the internal pores and cracks of mortar test block increases significantly. The maximum total substitution rate of regenerated micropowder and fly ash to cement is 40%(mass fraction).

Construction and Mix Ratio Optimization of Two Kinds of Ternary Gelling Systems

JING Biao, ZHANG Kaifeng, SANG Guochen, TONG Xiaogen, ZHU Wangke

2024, 43(5):  1822-1831. 

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In order to ensure the performance of concrete materials and achieve low-carbon and green development, two kinds of ternary cementitious systems were prepared by replacing 55% (mass fraction) cement (C) with auxiliary cementitious materials (SCMs) such as slag powder (GS), fly ash (FA) and limestone powder (LS), namely fly ash-slag powder-cement system (FGC) and limestone powder-slag powder-cement system (LGC). The influence of the proportion changes of FA-GS and LS-GS in system on compactness, workability, and strength of ternary cementitious material powder was studied, and the optimum mix ratio of ternary cementitious system was determined by microstructure analysis. The results show that as the proportion of GS in the two ternary cementitious systems increases, the compactness and flowability of sample slightly decrease, while the compressive strength, flexural strength, and environmental benefits of sample gradually increase. When the mass ratio of FA-GS and LS-GS is both 3∶8, the middle and late strength of mortar samples prepared by the two cementitious systems can be close to or even higher than that of pure cement samples.

Influences of Different Parent Soils on Microstructure and Strength of Cemented Soil

XIONG Jiagui, LI Yan, HU Songtao, LIAO Cheng, ZHOU Min, WANG Jinhui, LUO Shaoyang

2024, 43(5):  1832-1839. 

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In order to explore the variation law of the strength of cemented soil with different combinations of multivariate variables, unconfined compressive strength tests were carried out on the common clayey soil, sandy soil and gravelly soil in Jiangxi Province under different mix schemes, and the microstructure of cemented soil was analyzed by SEM. The results show that among the three types of cemented soil with optimal water content, the cemented soil with 21% cement inclusion ratio (mass fraction, the same below), 0.5 water-cement ratio, and 100% sand and gravel content has the highest compressive strength, with more C-S-H gel content, fewer pores, and more granular skeleton in the sand and gravel matrix.

Effects of Lightweight FACs on Properties of HPMC/Cement-Based Composite Porous Thermal Insulation Materials

WANG Jianlong, MA Bing, AN Qiaoxia, DU Yiyun, XIAO Tao, CHEN Kun

2024, 43(5):  1840-1849. 

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In order to obtain hydroxypropyl methyl cellulose (HPMC)/cement-based composite porous thermal insulation materials with good performance, the effects of different amounts of fly ash cenospheres(FACs) on the mechanical properties, thermal conductivity, dry density and water absorption of HPMC/cement-based composite porous thermal insulation materials were studied. At the same time, SEM, XRD and image analysis software were used to characterize the pore structure characteristics of composites. The results show that with the increase of FACs content, the thermal conductivity decreases first and then increases, and the compressive strength increases first and then decreases. When the FACs content is 9.0%(mass fraction), the thermal conductivity of composites is the smallest, which is 0.094 W/(m·K). Under this blending ratio, the 28 d compressive strength is 1.58 MPa, and the dry density is 418.9 kg/m³. When the FACs content is 18.0%, the compressive strength of composites is the best, the 28 d compressive strength is 2.15 MPa, the thermal conductivity is 0.101 W/(m·K), and the dry density is 431.0 kg/m³. With the increase of FACs content, the proportion of pores less than 300 μm in composites increases gradually,and the average pore size shows a decreasing trend.

Establishment and Simulation of Single Fiber Pull-Out Test Based on Lattice Model Theory

ZHAO Xiangpeng, LI Hui, YANG Qingyuan, LIU Yuanzhen, GE Zhi, JIANG Nengdong, ZHANG Hongzhi

2024, 43(5):  1850-1858. 

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The single fiber pull-out test of cement-based materials requires mechanical loading instruments with high precise, but the test operation is complicated, thus many laboratories do not have the ability to test. In order to slove this question, the discrete lattice model was adopted to simulate the pull-out process of single fiber from cementitious matrix using the stepwise method, and the fiber pull-out load-displacement response curve was obtained. The model was verified by the experimental data in the literature, and it is found that the simulation method can simulate the single fiber pull-out process and load-displacement curve. The influences of fiber direction, elastic modulus of fiber and interfacial bond strength on the pull-out load-displacement response curve were investigated using the model. The simulation results can be further used to study the influences of various factors on test results under different boundary conditions. The simulated results can be used to calculate the single-crack fiber bridging relationship of engineered cement-based composite, providing theoretical support for design of high toughness engineering cement-based composites.

Pore Structure Fractal Characteristics of PVA Fiber Concrete under Salt Erosion and Freeze-Thaw Cycle

WU Hao, XUE Weipei, WANG Zhongjian

2024, 43(5):  1859-1866. 

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To study the effect of polyvinyl alcohol (PVA) fibers on pore structure of concrete and its connection with frost resistance performance, the microscopic pore structure of PVA fiber concrete under the action of freeze-thaw cycle was tested by nuclear magnetic resonance (NMR) technology, the NMR T₂ spectrum and the change rule of pore distribution were analysized, and the pore fractal characteristics were explored based on fractal theory to reveal the relationship between the pore structure of PVA fiber concrete under the action of freeze-thaw cycle and fractal dimension. The relationship between pore structure and fractal dimension of PVA fiber concrete under the freeze-thaw cycle was revealed. The results show that PVA fiber concrete shows better frost resistance in the pre-freeze-thaw cycle period. The number and percentage of medium pores (100＜r≤1 000 nm) and large pores (r＞1 000 nm) increase, which weaken the frost resistance of PVA fiber concrete. The PVA fiber concrete has a certain fractal characteristic, and the fractal dimension D_max increases before five times freeze-thaw cycles and decreases with the increase of freeze-thaw cycles times.

Effect of Steel-Polyacrylonitrile Fiber Content on Fluidity and Mechanical Properties of Self-Compacting Concrete

HUO Rui, MA Qinyong, ZHANG Hongpeng, LI Biao

2024, 43(5):  1867-1877. 

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In order to analyze the effects of hybrid fibers on working performance and mechanical properties of self-compacting concrete (SCC), collapse expansion degree, J-ring collapse expansion degree, V-shaped funnel passing time and cube compressive strength of SCC with different steel fiber (SF) content (0%, 0.4%, 0.8% and 1.2%, volume fraction) and polyacrylonitrile fiber (PAN) content (0%, 0.04%, 0.08% and 0.12%, volume fraction) at different curing ages (7 and 28 d) were tested, and the microstructure of SCC was analyzed by scanning electron microscopy (SEM). The results show that with the increase of fiber content, fluidity and pore passing ability of SCC decrease, and the segregation resistance of SCC is improved. The improvement effect of SF on 7 d compressive strength of SCC is more significant than that of PAN. The mixed fiber has a more obvious effect on compressive strength of early SCC than single-doped fiber, and the mixed fiber can also effectively improve the toughness and ductility of SCC.

Solid Waste and Eco-Materials

Mix Proportion Optimization and Performance Study of Manufactured Sand Road Concrete Based on Response Surface Methodology

WANG Huibin, CUI Tong, CHEN Jie, WANG Wei, TAN Kanghao, YANG Donglai, ZHANG Tongsheng

2024, 43(5):  1878-1888. 

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To realize the mix proportion design of multi-objective performance of manufactured sand concrete, the Box-Behnken response surface methodology was used to design the experiment, and the effects of stone powder content, slurry volume fraction and water-binder ratio on slump, 28 d compressive strength and wear loss of manufactured sand road concrete were studied. Micro-structure analysis of the hardened paste was conducted using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results demonstrate that the regression models established using the response surface methodology accurately predict the relationships between various factors and performance parameters, with an accuracy exceeding 95%. Among the factors considered, the water-binder ratio has the most significant impact on the slump and compressive strength, while its influence on the wear loss is relatively minor. Through optimization, the best mix proportion for manufactured sand road concrete is found to be a water-binder ratio of 0.36, a slurry volume fraction of 25% and stone powder content of 10% (by weight). Furthermore, the stone powder content of less than 10% can improve the interface transition zone, contributing to the enhancement of the concrete mechanical properties.

Effect of CO₂-Mineralized High-Calcium Fly Ash on Mechanical Properties and Micro-Structure of Cement Mortar

HUANG Huanghuang, CHEN Tiefeng, GAO Xiaojian

2024, 43(5):  1889-1896. 

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To improve the volume stability and hydration activity of high-calcium fly ash (HFA), CO₂ mineralization treatment was applied in this paper. The CO₂ uptake percentage and free CaO content of HFA undergone different CO₂ mineralization duration were experimentally determined. The influence of CO₂-mineralized HFA on hydration heat, mechanical properties and pore structure of cement mortar was investigated. The results show that after 12 h of CO₂ mineralization modification treatment, the carbon sequestration of high calcium fly ash exceeds 10% (mass fraction), and the content of free calcium oxide in high calcium fly ash is significantly reduced. As the prolongation of CO₂mineralization, the hydration induction period of cement slurry mixed with HFA is shortened, and the early hydration heat release is significantly reduced. CO₂ mineralization can also mitigate the adverse impacts of HFA on mechanical strength, as well as improving the pore structure of cement mortar by reducing porosity and volume fraction of large capillary pores. Besides, CO₂-mineralized HFA provides more nucleation sites for precipitation of C-S-H, accelerating the early hydration reaction of cement paste.

Experimental Study on Sound Barrier Performance of Fly Ash Ceramsite Lightweight Concrete

GENG Limin, DU Hongxiu, NIE Xiaoqing, ZHOU Xingyu, YAN Changhao, LEI Yibin

2024, 43(5):  1897-1905. 

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Concrete is a widely used building material that can be prepared using a variety of solid waste. In this study, fly ash ceramsite was used as lightweight aggregate, and cement-fly ash-silica fume-coal metakaolin was used as composite cementitious material to prepare fly ash ceramsite lightweight concrete for sound barrier. The mechanical properties, sound absorption performance and carbonation resistance of fly ash ceramsite lightweight concrete were studied. The results show that when the total content of fly ash-silica fume-coal metakaolin is 10% of total mass of cementitious materials, the mechanical properties and carbonation resistance of samples are improved, and the sound absorption performance is reduced. With the further increase of fly ash-silica fume-coal metakaolin content, the mechanical properties and carbonation resistance of samples decrease, and sound absorption performance increases. The sound absorption coefficient changes little at 1 500 Hz and below, and the sound absorption effect is the best at 2 000 Hz. The average sound absorption coefficient of sample is 0.44~0.58, and the noise reduction coefficient is 0.74~0.89.

Properties of Basalt Fiber-Rubber Concrete

LIU Tao, LYU Jun, DENG Xuyan, WANG Shaoming, YU Bentian

2024, 43(5):  1906-1916. 

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In order to solve the problems of easy shrinkage cracking and freeze-thaw failure of concrete on the pavement of plateau airport, the mechanical properties, early shrinkage and frost resistance of concrete with different volumes of basalt fibers and different substitution rates rubber powder were studied. The mechanism of action of basalt fibers and rubber powder was explained by nuclear magnetic resonance and scanning electron microscopy, and an early shrinkage model of concrete considering the content of basalt fibers and rubber particles was established. The results show that compared with the baseline concrete, the 7 and 28 d flexural strength of the concrete with 0.3% (volume fraction, the same below) basalt fibers and 10% (volume substitution rate of sand, the same below) rubber particles increases by 13.6% and 11.8%, the 7 and 28 d compressive strength increases by 26.7% and 18.1%, the shrinkage rate reduces by 54.7% in 72 h. The mass loss rate reduces by 67.0%, and the loss rate of dynamic elastic modulus reduces by 10.4% after 300 freeze-thaw cycles. Basalt fibers can inhibit the expansion of microcracks in the concrete matrix, bear part of the shrinkage stress. The effects of filling, water storage and air entrainment of elastomer rubber particles optimize the pore structure of the matrix, delay the evaporation of water, relieve the frost heave pressure, improve the mechanical properties and frost resistance, and decrease the early shrinkage of concrete. The established shrinkage model can better reflect the early shrinkage characteristics of basalt fiber-rubber concrete.

Experimental Study on Mineral Powder Composite Solidified Saline Soil Based on Response Surface Method

WANG Yonghui, ZHU Lianyong, WANG Cheng, WANG Chao, PENG Yongqian

2024, 43(5):  1917-1927. 

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The use of mineral powder to reinforce saline soil effectively enhances the strength of saline soil, and reduces the solubility of saline soil foundations. However, the stability of mineral powder under normal temperature conditions is consistent, and its potential reactivity needs to be activated. Addressing this issue, mineral powder was used as a precursor, and the effect of different proportion of desulfurization gypsum-sodium hydroxide-carbide slag (DG-NaOH-CS, DNC) curing agents on the mechanical properties, durability and micro-mechanisms of mineral powder composite solidified saline soil was investigated. The results show that the optimal mix proportion of desulfurization gypsum, sodium hydroxide, and carbide slag is 6.03∶0.63∶4.24 (mass ratio). Based on this optimal mix proportion, the 28 d unconfined compressive strength mean value of DNC-modified soil is 14.16 MPa, with the response surface model predicted value of 14.08 MPa, indicating good correlation between predicted and experimental values. Compared to the same proportion of cement solidified soil, DNC-modified soil exhibits better compressive strength, resistance to freeze-thaw cycles and resistance to wet-dry cycles. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis shows that the DNC curing agent produces a large amount of hydrated calcium silicate (C-S-H), hydrated calcium aluminate (C-A-H), and ettringite (AFt) cementitious materials within the specimen, filling the internal pores of the soil and thereby further enhancing the strength of solidified soil.

Ceramics

Preparation and Research of High-Toughness C/C Composites

ZHANG Ze, ZHANG Mingyu, FANG Wanxian, XU Ping, ZENG Chen, GAO Ying, SU Zhean, HUANG Qizhong

2024, 43(5):  1928-1936. 

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C/C composites are a new type of high-performance composites, but their shortcomings of high brittleness and poor toughness limit their wide application. Therefore, in this study, three kinds of C/C composites were designed and prepared using the chemical vapor infiltration (CVI) method with matrix carbon: rough layer, smooth layer, and rough layer/isotropic layer band-structured pyrolytic carbon(PyC), respectively. And the microstructures, fracture behaviors, and toughening mechanisms of C/C composites were investigated. The results indicate that the flexural strength of the three C/C composites is 189.1, 191.5, and 233.5 MPa, respectively. The C/C composites with rough layer and band-structured carbon matrix are pseudoplastic fractures. In contrast, the C/C composites with smooth layer carbon matrix are brittle fractures. Compared to the C/C composites with rough layer carbon matrix, the C/C composites with band-structured carbon matrix show a significant increase in toughness through interfacial sliding between the different structured pyrolytic carbon, which increases strain amount by about 70%. Therefore, the toughness of C/C composites can be effectively optimized by controlling the parameters of the CVI process to achieve band-structured pyrolytic carbon preparation.

Sintering Property and Anti-Ablation Resistance of ZrB₂-SiC Ceramics Modified by CeO₂/MoSi₂

FANG Wanxian, ZENG Chen, ZHANG Ze, ZHANG Mingyu, HUANG Qizhong, GAO Ying

2024, 43(5):  1937-1949. 

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Pressureless sintered ZrB₂-SiC ceramics can be prepared as complex shaped component. But they are challenging to densify and have poor anti-ablation resistance. Therefore, there is an urgent need to investigate effective sintering aids to improve the densification of ceramics. ZrB₂-SiC ceramics were prepared by pressureless sintered at 1 850 ℃ for 1 h using CeO₂ and MoSi₂ as sintering aids. The effects of CeO₂ and MoSi₂ on sintering properties and anti-ablation resistance of ZrB₂-SiC ceramics were investigated. The results show that sintering properties and anti-ablation resistance of ZrB₂-SiC ceramics are best when the ratio of CeO₂ and MoSi₂ in 5% (volume fraction) sintering aid is 1∶1. Sintering aids form a Ce-Mo liquid phase during the sintering process. Ceramic particles are rearranged and mass transferred under the surface tension of the liquid phase. The Ce-Mo liquid phase promotes the formation of sintered necks under capillary forces, filles the interstices of the ceramic particles and reduces the grain boundary energy of the ceramic grains to facilitate the densification process. ZrB₂-SiC ceramics are ultimately obtained with an density of 5.02 g/cm³, a relative density of 89.71%, and a Vickers hardness of 14.04 GPa. The actual density and Vickers hardness increases by 53% and 43%, respectively, compared to when no sintering aid is added. During the ablation process, CeO₂ and MoSi₂ supplemented SiO₂ in appropriate amounts to promote self-healing of the glassy phase with suitable viscosity and improve the stability of ZrO₂. The mass ablation rate and the line ablation rate are -1.62 mg/s and 0.33 μm/s, respectively.

Effect of Alumina Filler on Thermal Conductivity of Insulating Coatings

LIU Kai, JIANG Hongyi, CAO Zeqi, GAO Shuai

2024, 43(5):  1950-1957. 

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Organic and inorganic composite silicate thermally conductive insulating coatings were prepared by using high modulus potassium silicate solution as a base material, alumina as a thermally conductive insulating filler, and silica-propylene emulsion and defoamer. The heat conduction behavior of insulating silicate coatings was studied by testing the thermal conductivity, volume resistivity, porosity, pore size distribution and elemental distribution changes of silicate coatings. The results show that the thermal conductivity of silicate insulating coatings is enhanced by appropriately increasing the mass fraction of alumina. The spherical morphology and large particle size of alumina filler are more favourable for the improvement of thermal conductivity of silicate insulating coatings. When the filler is spherical alumina with particle size of 2.9 μm and its mass fraction is 37.5%, the thermal conductivity of coating is up to 1.072 W/(m·K), the volume resistivity is more than 10⁸ Ω·m, and the thermal conductivity and insulating performance of coating reaches the best.

Refractory Materials

Effect of Three Types of Mullite on Corrosion Resistance of Refractories to Na₂CO₃ Melt

XU Zhigang, XIA Yi, MU Yizhao

2024, 43(5):  1958-1964. 

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The main reason for the damage of refractories is the penetration and corrosion by alkali ions such as K⁺ and Na⁺ in chemical waste liquid. Effective inhibition of alkali melt penetration is helpful to improve the service life of heat treatment equipment, but the method of simply reducing porosity may deteriorate its thermal shock stability. In this paper, the wetting, corrosion and penetration processes of refractories by Na₂CO₃ melt were studied, and the difference of alkali penetration resistance of different refractories was discussed from the point of view of wettability. Therefore, three types of mullite (high purity sintered mullite, fused mullite and ordinary sintered mullite), andalusite and clay were used as raw materials to prepare refractories by mechanical press forming and high temperature sintering. The alkali corrosion experiment was carried out at 900 ℃ by static crucible method with Na₂CO₃ as alkali corrosive agent. The phase and microstructure of the specimens before and after alkali corrosion were analyzed by X-ray diffractometer and scanning electron microscope, and the wettability of alkali melt to different substrates was tested. The results show that all materials are not damaged, showing excellent corrosion resistance. The ability of each group of specimens to resist the penetration of Na₂CO₃ melt is different. The specimens prepared by high purity sintered mullite have the best corrosion and penetration resistance, while the specimens prepared by fused mullite and ordinary sintered mullite have poor penetration resistance, which is related to the wetting ability of Na₂CO₃ melt to them. In this experiment, the difference of alkali corrosion resistance between refractories is analyzed from the perspective of high temperature wettability, which provided a new idea and theoretical basis for the research and production of aluminum-silicon refractories with excellent corrosion resistance.