The Experts below are selected from a list of 11706 Experts worldwide ranked by ideXlab platform

Gong Wang - One of the best experts on this subject based on the ideXlab platform.

  • Additive manufacturing of SiBCN/Si3N4w composites from preceramic polymers by Digital Light Processing
    RSC Advances, 2020
    Co-Authors: Yu Bei Zhang, Rui Dou, Weijian Han, Wenyan Duan, Tong Zhao, Li Wang, Gong Wang
    Abstract:

    The application of advanced ceramic materials is limited by their brittleness and complicated manufacturing methods. Three-dimensional (3D) printing has emerged as a new method for the fabrication of complex-shaped ceramics. Herein, a type of printable slurry composed of SiBCN preceramic polymers and high-volume fractions of Si3N4 whiskers (up to 60 wt% of polymer) was prepared, and subsequently printed via Digital Light Processing (DLP) technology. We successfully manufactured complex-structured ceramic composites and achieved high bending strength (∼180 MPa). The linear shrinkage and mass loss of the ceramic material were both significantly reduced after the introduction of whiskers. The properties and structure of the printed parts pyrolyzed at different temperatures were compared, and the relationship between the microstructure and mechanical properties discussed.

  • additive manufacturing of sibcn si3n4w composites from preceramic polymers by Digital Light Processing
    RSC Advances, 2020
    Co-Authors: Yu Bei Zhang, Rui Dou, Weijian Han, Wenyan Duan, Tong Zhao, Li Wang, Gong Wang
    Abstract:

    The application of advanced ceramic materials is limited by their brittleness and complicated manufacturing methods. Three-dimensional (3D) printing has emerged as a new method for the fabrication of complex-shaped ceramics. Herein, a type of printable slurry composed of SiBCN preceramic polymers and high-volume fractions of Si3N4 whiskers (up to 60 wt% of polymer) was prepared, and subsequently printed via Digital Light Processing (DLP) technology. We successfully manufactured complex-structured ceramic composites and achieved high bending strength (∼180 MPa). The linear shrinkage and mass loss of the ceramic material were both significantly reduced after the introduction of whiskers. The properties and structure of the printed parts pyrolyzed at different temperatures were compared, and the relationship between the microstructure and mechanical properties discussed.

  • partially stabilized zirconia moulds fabricated by stereolithographic additive manufacturing via Digital Light Processing
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2020
    Co-Authors: Li Wang, Weizhe Tang, Gong Wang, Wenyan Duan, Xiaodong Liu, Rui Dou
    Abstract:

    Abstract Partially stabilized zirconia (PSZ) moulds for aluminium casting were fabricated by stereolithographic additive manufacturing via Digital Light Processing (DLP). Green parts were fabricated on DLP equipment using curable ceramic suspension. These suspensions were studied by performing photopolymerisable and rheological characterisations. Thermogravimetry (TGA) was used to analyse thermal stability of the suspension. Phase composition of sintered parts was determined by X-ray diffraction (XRD), while mechanical properties of green and sintered parts were studied by three-point bending testing. Flexural strength and Young's modulus of sintered parts were determined to be 803.7 ± 59 MPa and 203.4 ± 17 GPa, and these values decreased to 41.5 ± 3.9 MPa and 3.1 ± 0.3 GPa for green parts, respectively. Large pores were suggested to originate failure, with fracture mode being predominantly intergranular. Finally, sintered ceramic investment moulds were prepared by stereolithography and subsequently used for aluminium casting purposes. Dimensions of green parts before sintering were about 0.5% smaller than design values within the plane of layers, and approximately 0.5% larger than design values perpendicular to the layers. Sintering shrinkage was around 22% in both directions. Surface roughness of sintered moulds and aluminium casting materials were quantitatively determined by profilometry.

  • Digital Light Processing of lunar regolith structures with high mechanical properties
    Ceramics International, 2019
    Co-Authors: Ming Liu, Weizhe Tang, Bingshan Liu, Rui Dou, Gong Wang, Wenyan Duan, Shan Li, Li Wang
    Abstract:

    It is highly desirable to establish an extraterrestrial base on the moon due to its practicality and scientific significance in the future space explorations, which promotes aerospace scientists to propose many conceivable fabrication methods. Herein, we fabricated architectural and functional structures with lunar regolith simulants via Digital Light Processing (DLP) technology, followed by sintering. The printing slurry was prepared by mixing CLRS-2 lunar regolith simulant powders with photocurable resins, and it exhibits excellent print-ability. The microstructures, chemical compositions, particle size distribution and thermal-gravimetric characteristic of the simulants were analyzed, respectively. The average compressive strength and flexure strength of the sintered samples are 428.1 MPa and 129.5 MPa respectively, which are higher than those reported in previous researches. These improved mechanical properties could be due to the small average diameter of pores and the chemical compositions.

  • Sintering of lunar regolith structures fabricated via Digital Light Processing
    Ceramics International, 2019
    Co-Authors: Rui Dou, Weizhe Tang, Wenyan Duan, Ming Liu, Li Wang, Yu Bei Zhang, Gong Wang
    Abstract:

    Abstract Architectural and functional structures composed of lunar regolith-simulant CLRS-2 were fabricated via Digital Light Processing and sintered at 1100 °C and 1150 °C under an air or argon atmosphere. This work is to investigate effects of atmosphere and temperature on mechanical properties, microstructure, and chemical composition of lunar regolith products. Samples sintered at 1150 °C in air underwent the highest sintering shrinkage and showed the best mechanical properties, likely due to the formation of glassy phase and dense structure following sintering. Conversely, argon-sintered samples exhibited lower density resulting from the lack of glassy phase. Phase analysis revealed varying chemical composition and therefore different underlying reaction mechanisms under two sintering atmospheres, indicating that sintering atmosphere significantly influences the microstructure and macroscopic properties of lunar regolith products.

Rui Dou - One of the best experts on this subject based on the ideXlab platform.

  • Additive manufacturing of SiBCN/Si3N4w composites from preceramic polymers by Digital Light Processing
    RSC Advances, 2020
    Co-Authors: Yu Bei Zhang, Rui Dou, Weijian Han, Wenyan Duan, Tong Zhao, Li Wang, Gong Wang
    Abstract:

    The application of advanced ceramic materials is limited by their brittleness and complicated manufacturing methods. Three-dimensional (3D) printing has emerged as a new method for the fabrication of complex-shaped ceramics. Herein, a type of printable slurry composed of SiBCN preceramic polymers and high-volume fractions of Si3N4 whiskers (up to 60 wt% of polymer) was prepared, and subsequently printed via Digital Light Processing (DLP) technology. We successfully manufactured complex-structured ceramic composites and achieved high bending strength (∼180 MPa). The linear shrinkage and mass loss of the ceramic material were both significantly reduced after the introduction of whiskers. The properties and structure of the printed parts pyrolyzed at different temperatures were compared, and the relationship between the microstructure and mechanical properties discussed.

  • additive manufacturing of sibcn si3n4w composites from preceramic polymers by Digital Light Processing
    RSC Advances, 2020
    Co-Authors: Yu Bei Zhang, Rui Dou, Weijian Han, Wenyan Duan, Tong Zhao, Li Wang, Gong Wang
    Abstract:

    The application of advanced ceramic materials is limited by their brittleness and complicated manufacturing methods. Three-dimensional (3D) printing has emerged as a new method for the fabrication of complex-shaped ceramics. Herein, a type of printable slurry composed of SiBCN preceramic polymers and high-volume fractions of Si3N4 whiskers (up to 60 wt% of polymer) was prepared, and subsequently printed via Digital Light Processing (DLP) technology. We successfully manufactured complex-structured ceramic composites and achieved high bending strength (∼180 MPa). The linear shrinkage and mass loss of the ceramic material were both significantly reduced after the introduction of whiskers. The properties and structure of the printed parts pyrolyzed at different temperatures were compared, and the relationship between the microstructure and mechanical properties discussed.

  • partially stabilized zirconia moulds fabricated by stereolithographic additive manufacturing via Digital Light Processing
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2020
    Co-Authors: Li Wang, Weizhe Tang, Gong Wang, Wenyan Duan, Xiaodong Liu, Rui Dou
    Abstract:

    Abstract Partially stabilized zirconia (PSZ) moulds for aluminium casting were fabricated by stereolithographic additive manufacturing via Digital Light Processing (DLP). Green parts were fabricated on DLP equipment using curable ceramic suspension. These suspensions were studied by performing photopolymerisable and rheological characterisations. Thermogravimetry (TGA) was used to analyse thermal stability of the suspension. Phase composition of sintered parts was determined by X-ray diffraction (XRD), while mechanical properties of green and sintered parts were studied by three-point bending testing. Flexural strength and Young's modulus of sintered parts were determined to be 803.7 ± 59 MPa and 203.4 ± 17 GPa, and these values decreased to 41.5 ± 3.9 MPa and 3.1 ± 0.3 GPa for green parts, respectively. Large pores were suggested to originate failure, with fracture mode being predominantly intergranular. Finally, sintered ceramic investment moulds were prepared by stereolithography and subsequently used for aluminium casting purposes. Dimensions of green parts before sintering were about 0.5% smaller than design values within the plane of layers, and approximately 0.5% larger than design values perpendicular to the layers. Sintering shrinkage was around 22% in both directions. Surface roughness of sintered moulds and aluminium casting materials were quantitatively determined by profilometry.

  • Superstretchable and Processable Silicone Elastomers by Digital Light Processing 3D Printing.
    ACS applied materials & interfaces, 2019
    Co-Authors: Tingting Zhao, Ying Zhang, Xin Yang, Xiaojuan Zhao, Chen Wang, Zhichao Liu, Rui Dou
    Abstract:

    A series of photosensitive resins suitable for the production of silicone elastomers through Digital Light Processing 3D printing are reported. Based on thiol–ene click reaction between a branched ...

  • Digital Light Processing of lunar regolith structures with high mechanical properties
    Ceramics International, 2019
    Co-Authors: Ming Liu, Weizhe Tang, Bingshan Liu, Rui Dou, Gong Wang, Wenyan Duan, Shan Li, Li Wang
    Abstract:

    It is highly desirable to establish an extraterrestrial base on the moon due to its practicality and scientific significance in the future space explorations, which promotes aerospace scientists to propose many conceivable fabrication methods. Herein, we fabricated architectural and functional structures with lunar regolith simulants via Digital Light Processing (DLP) technology, followed by sintering. The printing slurry was prepared by mixing CLRS-2 lunar regolith simulant powders with photocurable resins, and it exhibits excellent print-ability. The microstructures, chemical compositions, particle size distribution and thermal-gravimetric characteristic of the simulants were analyzed, respectively. The average compressive strength and flexure strength of the sintered samples are 428.1 MPa and 129.5 MPa respectively, which are higher than those reported in previous researches. These improved mechanical properties could be due to the small average diameter of pores and the chemical compositions.

Li Wang - One of the best experts on this subject based on the ideXlab platform.

  • Additive manufacturing of SiBCN/Si3N4w composites from preceramic polymers by Digital Light Processing
    RSC Advances, 2020
    Co-Authors: Yu Bei Zhang, Rui Dou, Weijian Han, Wenyan Duan, Tong Zhao, Li Wang, Gong Wang
    Abstract:

    The application of advanced ceramic materials is limited by their brittleness and complicated manufacturing methods. Three-dimensional (3D) printing has emerged as a new method for the fabrication of complex-shaped ceramics. Herein, a type of printable slurry composed of SiBCN preceramic polymers and high-volume fractions of Si3N4 whiskers (up to 60 wt% of polymer) was prepared, and subsequently printed via Digital Light Processing (DLP) technology. We successfully manufactured complex-structured ceramic composites and achieved high bending strength (∼180 MPa). The linear shrinkage and mass loss of the ceramic material were both significantly reduced after the introduction of whiskers. The properties and structure of the printed parts pyrolyzed at different temperatures were compared, and the relationship between the microstructure and mechanical properties discussed.

  • additive manufacturing of sibcn si3n4w composites from preceramic polymers by Digital Light Processing
    RSC Advances, 2020
    Co-Authors: Yu Bei Zhang, Rui Dou, Weijian Han, Wenyan Duan, Tong Zhao, Li Wang, Gong Wang
    Abstract:

    The application of advanced ceramic materials is limited by their brittleness and complicated manufacturing methods. Three-dimensional (3D) printing has emerged as a new method for the fabrication of complex-shaped ceramics. Herein, a type of printable slurry composed of SiBCN preceramic polymers and high-volume fractions of Si3N4 whiskers (up to 60 wt% of polymer) was prepared, and subsequently printed via Digital Light Processing (DLP) technology. We successfully manufactured complex-structured ceramic composites and achieved high bending strength (∼180 MPa). The linear shrinkage and mass loss of the ceramic material were both significantly reduced after the introduction of whiskers. The properties and structure of the printed parts pyrolyzed at different temperatures were compared, and the relationship between the microstructure and mechanical properties discussed.

  • partially stabilized zirconia moulds fabricated by stereolithographic additive manufacturing via Digital Light Processing
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2020
    Co-Authors: Li Wang, Weizhe Tang, Gong Wang, Wenyan Duan, Xiaodong Liu, Rui Dou
    Abstract:

    Abstract Partially stabilized zirconia (PSZ) moulds for aluminium casting were fabricated by stereolithographic additive manufacturing via Digital Light Processing (DLP). Green parts were fabricated on DLP equipment using curable ceramic suspension. These suspensions were studied by performing photopolymerisable and rheological characterisations. Thermogravimetry (TGA) was used to analyse thermal stability of the suspension. Phase composition of sintered parts was determined by X-ray diffraction (XRD), while mechanical properties of green and sintered parts were studied by three-point bending testing. Flexural strength and Young's modulus of sintered parts were determined to be 803.7 ± 59 MPa and 203.4 ± 17 GPa, and these values decreased to 41.5 ± 3.9 MPa and 3.1 ± 0.3 GPa for green parts, respectively. Large pores were suggested to originate failure, with fracture mode being predominantly intergranular. Finally, sintered ceramic investment moulds were prepared by stereolithography and subsequently used for aluminium casting purposes. Dimensions of green parts before sintering were about 0.5% smaller than design values within the plane of layers, and approximately 0.5% larger than design values perpendicular to the layers. Sintering shrinkage was around 22% in both directions. Surface roughness of sintered moulds and aluminium casting materials were quantitatively determined by profilometry.

  • Digital Light Processing of lunar regolith structures with high mechanical properties
    Ceramics International, 2019
    Co-Authors: Ming Liu, Weizhe Tang, Bingshan Liu, Rui Dou, Gong Wang, Wenyan Duan, Shan Li, Li Wang
    Abstract:

    It is highly desirable to establish an extraterrestrial base on the moon due to its practicality and scientific significance in the future space explorations, which promotes aerospace scientists to propose many conceivable fabrication methods. Herein, we fabricated architectural and functional structures with lunar regolith simulants via Digital Light Processing (DLP) technology, followed by sintering. The printing slurry was prepared by mixing CLRS-2 lunar regolith simulant powders with photocurable resins, and it exhibits excellent print-ability. The microstructures, chemical compositions, particle size distribution and thermal-gravimetric characteristic of the simulants were analyzed, respectively. The average compressive strength and flexure strength of the sintered samples are 428.1 MPa and 129.5 MPa respectively, which are higher than those reported in previous researches. These improved mechanical properties could be due to the small average diameter of pores and the chemical compositions.

  • Sintering of lunar regolith structures fabricated via Digital Light Processing
    Ceramics International, 2019
    Co-Authors: Rui Dou, Weizhe Tang, Wenyan Duan, Ming Liu, Li Wang, Yu Bei Zhang, Gong Wang
    Abstract:

    Abstract Architectural and functional structures composed of lunar regolith-simulant CLRS-2 were fabricated via Digital Light Processing and sintered at 1100 °C and 1150 °C under an air or argon atmosphere. This work is to investigate effects of atmosphere and temperature on mechanical properties, microstructure, and chemical composition of lunar regolith products. Samples sintered at 1150 °C in air underwent the highest sintering shrinkage and showed the best mechanical properties, likely due to the formation of glassy phase and dense structure following sintering. Conversely, argon-sintered samples exhibited lower density resulting from the lack of glassy phase. Phase analysis revealed varying chemical composition and therefore different underlying reaction mechanisms under two sintering atmospheres, indicating that sintering atmosphere significantly influences the microstructure and macroscopic properties of lunar regolith products.

Changjiang Wang - One of the best experts on this subject based on the ideXlab platform.

  • fabrication and properties of zirconia hydroxyapatite composite scaffold based on Digital Light Processing
    Ceramics International, 2020
    Co-Authors: Ying Cao, Tianshu Shi, Ruoyu Chen, Huixin Liang, Zongjun Tian, Chen Jiao, Anchao Zou, Youwen Yang, Zhen Wei, Changjiang Wang
    Abstract:

    Abstract Zirconia and hydroxyapatite(HA) are two typical implant materials, which have the advantages of excellent mechanical strength and good biological activity respectively. It was found that composite material had good biocompatibility and mechanical strength compared to the single material. In this paper, the porous scaffolds of ZrO2/HA composite were formed by Digital Light Processing (DLP) technology and their performance were evaluated. Cell experiments showed that the addition of HA had a positive effect on cell proliferation and differentiation. Mechanical tests showed that the composite scaffold with 10 wt% HA had the best compressive capacity due to the pinning and bridging effect of a small amount of HA grains. When scaffolds were immersed in the simulated body fluid (SBF), the compressive strengths of the composite scaffolds decreased within the first 14 days and gradually increased after 14 days. The reason for this phenomenon was the degradation of calcium phosphate components and the deposition of apatite. By the 28th day, the compressive strengths of all the composite scaffolds increased to over 20 MPa, close to that of the zirconia scaffolds during the same period (25 MPa). The compressive strengths of all scaffolds met the requirement of cancellous bone during the entire soaking period, and the composite scaffolds have potential application value in bone repair.

  • Preparation of Al2O3-ZrO2 scaffolds with controllable multi-level pores via Digital Light Processing
    Journal of the European Ceramic Society, 2020
    Co-Authors: Chen Jiao, Tianshu Shi, Deqiao Xie, Ruoyu Chen, Huixin Liang, Lida Shen, Changjiang Wang, Ying Cao, Zongjun Tian
    Abstract:

    Abstract Multi-level porous material based on additive manufacturing, is a potentially disruptive material across multiple industries, including medical implants, thermal insulation and filtration. In this study, we propose a novel approach to fabricate materials with controllable pores via Digital Light Processing (DLP) and decomposition of Al(OH)3. DLP can be used to fabricate macro pores bigger than 300 μm. And the decomposition of Al(OH)3 can result in micro pores of about 1 μm inside the scaffolds. The process parameters of curing, debinding and sintering temperature (1100−1500 ℃) of ceramic scaffolds with containing proportion of Al(OH)3 (0−60 wt.%) were examined. The results indicated multi-level porous ceramic scaffold has controllable porosity and pore size distribution and meets the requirement of implant strength. Biological test show that ceramic scaffolds with multi-level pores promoted osteoblast proliferation and adhesion. The multi-level porous ceramic scaffolds prepared by DLP and decomposition of Al(OH)3 have great prospects for the application in bone implants.

  • Fabrication and properties of zirconia/hydroxyapatite composite scaffold based on Digital Light Processing
    Ceramics International, 2020
    Co-Authors: Ying Cao, Tianshu Shi, Ruoyu Chen, Huixin Liang, Zongjun Tian, Chen Jiao, Anchao Zou, Youwen Yang, Zhen Wei, Changjiang Wang
    Abstract:

    Abstract Zirconia and hydroxyapatite(HA) are two typical implant materials, which have the advantages of excellent mechanical strength and good biological activity respectively. It was found that composite material had good biocompatibility and mechanical strength compared to the single material. In this paper, the porous scaffolds of ZrO2/HA composite were formed by Digital Light Processing (DLP) technology and their performance were evaluated. Cell experiments showed that the addition of HA had a positive effect on cell proliferation and differentiation. Mechanical tests showed that the composite scaffold with 10 wt% HA had the best compressive capacity due to the pinning and bridging effect of a small amount of HA grains. When scaffolds were immersed in the simulated body fluid (SBF), the compressive strengths of the composite scaffolds decreased within the first 14 days and gradually increased after 14 days. The reason for this phenomenon was the degradation of calcium phosphate components and the deposition of apatite. By the 28th day, the compressive strengths of all the composite scaffolds increased to over 20 MPa, close to that of the zirconia scaffolds during the same period (25 MPa). The compressive strengths of all scaffolds met the requirement of cancellous bone during the entire soaking period, and the composite scaffolds have potential application value in bone repair.

  • additive manufacturing of monolithic microwave dielectric ceramic filters via Digital Light Processing
    Electronics, 2019
    Co-Authors: Qingrong Liu, Deqiao Xie, Lida Shen, Changjiang Wang, Mingbo Qiu, Chen Jiao, Yun Ye, Meng Xiao, Jianfeng Zhao
    Abstract:

    Microwave dielectric ceramics are employed in filters as electromagnetic wave propagation media. Based on additive manufacturing (AM) techniques, microwave dielectric ceramic filters with complex and precise structures can be fabricated to satisfy filtering requirements. Digital Light Processing (DLP) is a promising AM technique that is capable of producing filters with high accuracy and efficiency. In this paper, monolithic filters made from Al2O3 and TiO2, with a molar ratio of 9:1 (0.9 Al2O3-0.1 TiO2), were fabricated by DLP. The difference in the dielectric properties between the as-sintered and post-annealed samples at different temperatures was studied. The experimental results showed that when sintered at 1550 °C for 2 h and post annealed at 1000 °C for 5 h, 0.9 Al2O3-0.1 TiO2 exhibited excellent dielectric properties: er = 12.4, Q × f = 111,000 GHz, τf = +1.2 ppm/°C. After comparing the measured results with the simulated ones in the passband from 6.5 to 9 GHz, it was concluded that the insertion loss (IL) and return loss (RL) of the filter meet the design requirements.

  • Additive manufacturing of hydroxyapatite bone scaffolds via Digital Light Processing and in vitro compatibility
    Ceramics International, 2019
    Co-Authors: Zibo Liu, Tianshu Shi, Deqiao Xie, Ruoyu Chen, Huixin Liang, Lida Shen, Changjiang Wang, Xiao Han, Zongjun Tian
    Abstract:

    The bioceramic material hydroxyapatite (HA) is widely used in the field of bone repair. Based on additive manufacturing (AM) techniques, HA is fabricated with complex geometry to satisfy biomedical application requirements. Digital Light Processing (DLP) is a promising AM technique that is capable of producing HA parts with high accuracy and efficiency. The fabrication of HA parts using DLP is investigated in this study. Properties of the HA ceramic slurry and the process parameters of curing, debinding, and sintering are initially examined. The mechanical properties, porosity, and shrinkage of the sintered samples is then investigated. The experimental results show that ceramic samples with density above 90%, microhardness up to 270 HV, and flexural strength of 41.3 MPa can be manufactured using the DLP method. Hydroxyapatite bone scaffolds are then prepared with pore sizes of 300–600 μm, porosity of about 49.8%, and compressive strength of 15.25 MPa, and the scaffolds are cultured with osteoblast precursor cells to detect biocompatibility. Results illustrate that the produced scaffolds possess strong biocompatibility and can promote osteoblast proliferation, adhesion, and differentiation. The HA bone scaffolds fabricated by DLP AM show strong potential to fulfill a constructive role in the medical field of human bone repair.

Zongjun Tian - One of the best experts on this subject based on the ideXlab platform.

  • fabrication and properties of zirconia hydroxyapatite composite scaffold based on Digital Light Processing
    Ceramics International, 2020
    Co-Authors: Ying Cao, Tianshu Shi, Ruoyu Chen, Huixin Liang, Zongjun Tian, Chen Jiao, Anchao Zou, Youwen Yang, Zhen Wei, Changjiang Wang
    Abstract:

    Abstract Zirconia and hydroxyapatite(HA) are two typical implant materials, which have the advantages of excellent mechanical strength and good biological activity respectively. It was found that composite material had good biocompatibility and mechanical strength compared to the single material. In this paper, the porous scaffolds of ZrO2/HA composite were formed by Digital Light Processing (DLP) technology and their performance were evaluated. Cell experiments showed that the addition of HA had a positive effect on cell proliferation and differentiation. Mechanical tests showed that the composite scaffold with 10 wt% HA had the best compressive capacity due to the pinning and bridging effect of a small amount of HA grains. When scaffolds were immersed in the simulated body fluid (SBF), the compressive strengths of the composite scaffolds decreased within the first 14 days and gradually increased after 14 days. The reason for this phenomenon was the degradation of calcium phosphate components and the deposition of apatite. By the 28th day, the compressive strengths of all the composite scaffolds increased to over 20 MPa, close to that of the zirconia scaffolds during the same period (25 MPa). The compressive strengths of all scaffolds met the requirement of cancellous bone during the entire soaking period, and the composite scaffolds have potential application value in bone repair.

  • Fabrication and properties of zirconia/hydroxyapatite composite scaffold based on Digital Light Processing
    Ceramics International, 2020
    Co-Authors: Ying Cao, Tianshu Shi, Ruoyu Chen, Huixin Liang, Zongjun Tian, Chen Jiao, Anchao Zou, Youwen Yang, Zhen Wei, Changjiang Wang
    Abstract:

    Abstract Zirconia and hydroxyapatite(HA) are two typical implant materials, which have the advantages of excellent mechanical strength and good biological activity respectively. It was found that composite material had good biocompatibility and mechanical strength compared to the single material. In this paper, the porous scaffolds of ZrO2/HA composite were formed by Digital Light Processing (DLP) technology and their performance were evaluated. Cell experiments showed that the addition of HA had a positive effect on cell proliferation and differentiation. Mechanical tests showed that the composite scaffold with 10 wt% HA had the best compressive capacity due to the pinning and bridging effect of a small amount of HA grains. When scaffolds were immersed in the simulated body fluid (SBF), the compressive strengths of the composite scaffolds decreased within the first 14 days and gradually increased after 14 days. The reason for this phenomenon was the degradation of calcium phosphate components and the deposition of apatite. By the 28th day, the compressive strengths of all the composite scaffolds increased to over 20 MPa, close to that of the zirconia scaffolds during the same period (25 MPa). The compressive strengths of all scaffolds met the requirement of cancellous bone during the entire soaking period, and the composite scaffolds have potential application value in bone repair.

  • Preparation of Al2O3-ZrO2 scaffolds with controllable multi-level pores via Digital Light Processing
    Journal of the European Ceramic Society, 2020
    Co-Authors: Chen Jiao, Tianshu Shi, Deqiao Xie, Ruoyu Chen, Huixin Liang, Lida Shen, Changjiang Wang, Ying Cao, Zongjun Tian
    Abstract:

    Abstract Multi-level porous material based on additive manufacturing, is a potentially disruptive material across multiple industries, including medical implants, thermal insulation and filtration. In this study, we propose a novel approach to fabricate materials with controllable pores via Digital Light Processing (DLP) and decomposition of Al(OH)3. DLP can be used to fabricate macro pores bigger than 300 μm. And the decomposition of Al(OH)3 can result in micro pores of about 1 μm inside the scaffolds. The process parameters of curing, debinding and sintering temperature (1100−1500 ℃) of ceramic scaffolds with containing proportion of Al(OH)3 (0−60 wt.%) were examined. The results indicated multi-level porous ceramic scaffold has controllable porosity and pore size distribution and meets the requirement of implant strength. Biological test show that ceramic scaffolds with multi-level pores promoted osteoblast proliferation and adhesion. The multi-level porous ceramic scaffolds prepared by DLP and decomposition of Al(OH)3 have great prospects for the application in bone implants.

  • Additive manufacturing of hydroxyapatite bone scaffolds via Digital Light Processing and in vitro compatibility
    Ceramics International, 2019
    Co-Authors: Zibo Liu, Tianshu Shi, Deqiao Xie, Ruoyu Chen, Huixin Liang, Lida Shen, Changjiang Wang, Xiao Han, Zongjun Tian
    Abstract:

    The bioceramic material hydroxyapatite (HA) is widely used in the field of bone repair. Based on additive manufacturing (AM) techniques, HA is fabricated with complex geometry to satisfy biomedical application requirements. Digital Light Processing (DLP) is a promising AM technique that is capable of producing HA parts with high accuracy and efficiency. The fabrication of HA parts using DLP is investigated in this study. Properties of the HA ceramic slurry and the process parameters of curing, debinding, and sintering are initially examined. The mechanical properties, porosity, and shrinkage of the sintered samples is then investigated. The experimental results show that ceramic samples with density above 90%, microhardness up to 270 HV, and flexural strength of 41.3 MPa can be manufactured using the DLP method. Hydroxyapatite bone scaffolds are then prepared with pore sizes of 300–600 μm, porosity of about 49.8%, and compressive strength of 15.25 MPa, and the scaffolds are cultured with osteoblast precursor cells to detect biocompatibility. Results illustrate that the produced scaffolds possess strong biocompatibility and can promote osteoblast proliferation, adhesion, and differentiation. The HA bone scaffolds fabricated by DLP AM show strong potential to fulfill a constructive role in the medical field of human bone repair.