共查询到20条相似文献,搜索用时 31 毫秒
1.
Marco Pelanconi Giovanni Bianchi Paolo Colombo Alberto Ortona 《Journal of the American Ceramic Society》2022,105(2):786-793
In this work, we report the fabrication of Silicon infiltrated Silicon Carbide (SiSiC) components by a hybrid additive manufacturing process. Selective laser sintering of polyamide powders was used to 3D print a polymeric preform with controlled relative density, which allows manufacturing geometrically complex parts with small features. Preceramic polymer infiltration with a silicon carbide precursor followed by pyrolysis (PIP) was used to convert the preform into an amorphous SiC ceramic, and five PIP cycles were performed to increase the relative density of the part. The final densification was achieved via liquid silicon infiltration (LSI) at 1500°C, obtaining a SiSiC ceramic component without change of size and shape distortion. The crystallization of the previously generated SiC phase, with associated volume change, allowed to fully infiltrate the part leading to an almost fully dense material consisting of β-SiC and Si in the volume fraction of 45% and 55% respectively. The advantage of this approach is the possibility of manufacturing SiSiC ceramics directly from the preceramic precursor, without the need of adding ceramic powder to the infiltrating solution. This can be seen as an alternative AM approach to Binder jetting and direct ink writing for the production of templates to be further processed by silicon infiltration. 相似文献
2.
Fabrication of Porous SiC Ceramics with Special Morphologies by Sacrificing Template Method 总被引:1,自引:0,他引:1
Sacrificial template technique is widely used in producing porous materials with controlled morphologies and tailored properties. In this paper, unique templates such as filters, carbon nanotube, carbon fiber and silica were used to make porous SiC ceramic with special morphologies. Template derived porous ceramic plates, SiC nano-net, fiber-inverse and bead-inverse porous SiC ceramic were successfully prepared from the preceramic precursor, polymethylsilane (PMS). The synthesis procedures were involved with the infiltration of the templates with appropriate concentration of the preceramic polymer, their curing, pyrolysis and subsequent template removal. The synthesized porous SiC was characterized by SEM, TEM, XRD and BET methods. 相似文献
3.
Unni Santhosh Jalees Ahmad Timothy Easler Yasser Gowayed 《Journal of the American Ceramic Society》2021,104(12):6108-6130
This work describes a physics-based model to simulate the polymer infiltration and pyrolysis (PIP) manufacturing process for ceramic matrix composites (CMCs). Models have been developed to characterize volumetric distribution of constituents and track porosity inside the composite at different PIP stages utilizing test data from TGA and DSC characterization of a commercial preceramic polymer. Laboratory experiments were done using C/SiC CMC specimens manufactured with a variable number of PIP cycles in order to obtain inputs for the models, and the analytical results have been shown to agree with porosity determined from physical measurements. 相似文献
4.
《Ceramics International》2019,45(11):14006-14014
Stereolithography based additive manufacturing provides a new route to produce ceramic architectures with complex geometries. In this study, 3D structured SiC ceramic architectures were fabricated by stereolithography based additive manufacturing combined with precursor infiltration and pyrolysis (PIP). Firstly, photosensitive SiC slurry was prepared. Then, stereolithography was conducted to fabricate complex-shaped green SiC parts. Polymer burn-out was subsequently performed, and porous SiC preforms were produced. After that, precursor infiltration and pyrolysis was used to improve the density and strength. Finally, 3D-structured SiC ceramic architectures with high accuracy and quality were obtained. It is believed that this study can give some fundamental understanding for the additive manufacturing of SiC ceramic structures. 相似文献
5.
Lianzhong Zhao Xiaofeng Wang Huiwen Xiong Kechao Zhou Dou Zhang 《Journal of the European Ceramic Society》2021,41(10):5066-5074
3D structured ceramics stemmed from preceramic polymers via additive manufacturing have attracted much attention recently. However, these polymers with high ceramic yield are so brittle that extrusion-based additive manufacturing techniques are hardly able to be utilized for assembling 3D structures. Herein, we developed a strategy to prepare feedstocks for these manufacturing techniques, i.e., utilizing a small amount of thermal-plastic polymer to optimize the preceramic polymer while good compatibility is required between the two polymers to ensure a homogeneous mixture. Polycarbosilane and polypropylene were selected as the representative materials. Polypropylene occupied a small proportion (≤5wt.%) and significantly improved the formability of the precursor. Three-dimensional SiC were obtained via fused deposition modeling combined with crosslinking and pyrolysis. The SiC ceramic filaments showed a mean tensile strength of 471 MPa. The strategy is also applicable to a large field of ceramic systems with corresponding precursor, such as sialon ceramic and multicomponent Si-based ceramics. 相似文献
6.
《Journal of the European Ceramic Society》2005,25(2-3):187-192
Preceramic polymers are enabling the development of a variety of advanced shaping methods which, in turn, make possible new and cost-effective approaches for the fabrication of composite materials. This opens new perspectives for the mass production of composites which might, for example, be used in cost-sensitive areas of application in the machine and automobile industries. In two examples it will be shown how preceramic polymers can be used to obtain both metal matrix composites (MMC) and ceramic matrix composites (CMC). Their properties will be discussed in particular with respect to the usage of a preceramic polymer.The first example shows an approach to manufacturing short-fibre-reinforced CMCs by means of a plastic forming technique which involves mixing of either carbon or SiC fibres, ceramic fillers and a viscous ceramic precursor. The precursor permits a fibre-reinforced ceramic with a low porosity to be obtained. The role of the precursor in the whole process and the resulting material properties will be discussed.The second example shows a method for fabricating porous SiC ceramic preforms which are subsequently infiltrated with aluminium to form a MMC. By using the precursor route, a machinable preform with tailored porosity can be produced. Correlations between precursor, preform and MMC properties will be drawn. 相似文献
7.
《Journal of the European Ceramic Society》2023,43(14):5871-5881
The fabrication of a wide range of polymer-derived ceramic parts with high geometric complexity through a novel hybrid additive manufacturing technique is presented in this article. The process that we introduced in a previous work uses the powder bed fusion technology to manufacture high porous polymeric preforms to be then converted into ceramics through preceramic polymer infiltration and pyrolysis. The cellular architectures of a rotated cube (strut-based) and a gyroid (sheet-based) with 25 mm diameter, 44 mm height and 67 % of geometric macroporosity were generated and used for the fabrication. The complex structures were 3D printed and polycarbosilane, polycarbosiloxane, polysilazane and furan liquid polymers were used to produce SiC, SiOC, SiCN and glassy carbon, respectively. Despite a linear shrinkage of about 24 %, the parts maintained their designed complex shape without deformations. The significant advantages of the proposed method are the maturity of powder bed fusion for polymers with respect to ceramic additive manufacturing techniques and the possibility to fabricate net-shape complex ceramic parts directly from preceramic precursors. 相似文献
8.
9.
《Ceramics International》2022,48(18):25833-25839
SiC aerogels are representative high-temperature ceramic aerogels that have demonstrated extensive potential utility in the thermal insulation field under extreme conditions. Although the efficient fabrication of monolithic and highly crystalline SiC aerogels is crucial, it remains highly challenging. Herein, a one-step pyrolysis strategy of a bridged polysilsesquioxane (BPSi) aerogel precursor is reported. The preceramic BP aerogel was prepared via a sol-gel method followed by vacuum drying, and the subsequent pyrolysis process conveniently converted the BPSi aerogel precursor into a SiC aerogel. This circumvents the need for harsh synthetic conditions, high-cost noble metal catalysts, special drying, and additional calcination processes. Furthermore, a competitive mechanism between the “gas-escape” caused by the volatilization of low molecular compounds and carbothermal reduction reaction, and the “volume-shrinkage” resulting from high-temperature sintering was proposed to explain the evolution of phase composition and pore hierarchy of BPSi-derived ceramic aerogels. 相似文献
10.
Development and Characterization of Continuous SiC Fiber‐Reinforced HfB2‐Based UHTC Matrix Composites Using Polymer Impregnation and Slurry Infiltration Techniques
下载免费PDF全文
![点击此处可从《International Journal of Applied Ceramic Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Clifford J. Leslie Emmanuel E. Boakye Kristin A. Keller Michael K. Cinibulk 《International Journal of Applied Ceramic Technology》2015,12(1):235-244
This paper discusses the development of continuous SiC fiber‐reinforced HfB2‐SiC composite laminates. A range of techniques, based on resin‐based precursors and slurries, for infiltrating porous SiC preforms with HfB2 powder were developed. While resin‐based precursors proved to be ineffective due to low HfB2 yield and poor adhesion, the slurry infiltration techniques were effective to varying degrees. The greatest pore filling and composite densities were achieved using pressure and vibration‐assisted pressure infiltration techniques. SiCf/HfB2‐SiC laminates were subsequently developed via lamination, cure and pyrolysis of fabrics using a HfB2‐loaded polymeric SiC precursor, followed by HfB2 slurry infiltration and preceramic polymer infiltration and pyrolysis (PIP). Repeated PIP processing, for 6–10 cycles, resulted in density increases, from the 3.03–3.22 g/cm3 range after HfB2 slurry infiltration, to 3.97–4.03 g/cm3 after PIP processing. Correspondingly, there was a decrease in open porosity from approximately 52% to less than 11%. The matrix consisted of discreet, lightly sintered HfB2 particles dispersed in SiC. The PIP SiC matrix was primarily nanocrystalline after 1300°C pyrolysis, but experienced grain growth with further heat treatment at 1600°C. 相似文献
11.
A. Baux S. Jacques A. Allemand G.L. Vignoles P. David T. Piquero M.-P. Stempin G. Chollon 《Journal of the European Ceramic Society》2021,41(6):3274-3284
We present here an original route for the manufacturing of SiC ceramics based on 3D printing, polymer impregnation and pyrolysis and chemical vapor deposition (CVD). The green porous elastomer structures were first prepared by fused deposition modeling (FDM) 3D-printing with a composite polyvinyl alcohol/elastomer wire and soaking in water, then impregnated with an allylhydridopolycarbosilane preceramic polymer. After crosslinking and pyrolysis, the polymer-derived ceramics were reinforced by CVD of SiC using CH3SiCl3/H2 as precursor. The multiscale structure of the SiC porous specimens was examined by X-ray tomography and scanning electron microscopy analyses. Their oxidation resistance was also studied. The pure and dense CVD-SiC coating considerably improves the oxidation resistance. 相似文献
12.
Corson L. Cramer Amy M. Elliott Edgar Lara-Curzio Alexis Flores-Betancourt Michael J. Lance Lu Han Jesse Blacker Artem A. Trofimov Hsin Wang Ercan Cakmak Kashif Nawaz 《Journal of the American Ceramic Society》2021,104(11):5467-5478
We report the physical and mechanical properties of ceramic composite materials fabricated by binder jet 3D printing (BJ3DP) with silicon carbide (SiC) powders, followed by phenolic resin infiltration and pyrolysis (IP) to generate carbon, and a final reactive silicon melt infiltration step. After two phenolic resin infiltration and pyrolysis cycles; porosity was less than 2%, Young's modulus was close to 300 GPa, and the flexural strength was 517.6 ± 24.8 MPa. However, diminishing returns were obtained after more than two phenolic resin infiltration and pyrolysis cycles as surface pores in carbon were closed upon the formation of SiC, resulting in reaction choking and residual-free carbon and porosity. The instantaneous coefficient of thermal expansion of the composite was found to be independent of the number of phenolic IP cycles and had values of between 4.2 and 5.0 ppm/°C between 300 and 1000℃, whereas the thermal conductivity was found to have a weak dependence on the number of phenolic IP cycles. While the manufacturing procedures described here yielded highly dense, gas impermeable, siliconized SiC composites with properties comparable to those of bulk siliconized silicon carbide processed according to conventional techniques, BJ3DP enables the manufacture of objects with complex shape, unlike conventional techniques. 相似文献
13.
Traditionally, SiC components with complex shapes are very difficult or even impossible to fabricate. This paper aims to develop a new manufacturing process, combining selective laser sintering (SLS), cold isostatic pressing (CIP) and polymer infiltration pyrolysis (PIP), to manufacture complex silicon carbide parts and improve the mechanical properties of silicon carbide ceramic parts. The density and porosity of SiC/SiC composites were measured. Furthermore, the mechanical properties of the specimens with cold isostatic pressing and the specimens without cold isostatic pressing were compared. The bending strength of the specimens with cold isostatic pressing was 201?MPa, and the elastic modulus was 1.27?GPa. And, the bending strength of the specimens without cold isostatic pressing was 142?MPa, and the elastic modulus was 0.88?GPa. Increasing the density of SiC/SiC can enhance the mechanical properties of SiC/SiC composites. 相似文献
14.
Processing and properties of Nextel™ 720 fiber reinforced alumina-zirconia ceramic matrix composites
《Ceramics International》2022,48(18):25849-25857
The continuous Nextel? 720 fiber-reinforced zirconia/alumina ceramic matrix composites (CMCs) were prepared by slurry infiltration process and precursor infiltration pyrolysis (PIP) process. The introduction of submicron zirconia powders into the aqueous slurry was optimized to offer comprehensively good sintering activity, high thermal resistance and good mechanical properties for the CMCs. Meanwhile, the zirconia and alumina preceramic polymers were used to strengthen the porous ceramic matrix through the PIP process. The final CMC sample achieved a high flexural strength of 200 MPa after one infiltration cycle of alumina preceramic polymer and thermal treatment at 1150 °C for 2 h. The flexural strength retention of the improved CMC sample was 104% and 89% respectively after thermal exposure at 1100 °C and 1200 °C for 24 h. 相似文献
15.
Sub-micrometer SiC particles were firstly added to the preceramic solution in the first infiltration step to enhance the mechanical properties of 2D Cf/SiC composites fabricated via polymer infiltration and pyrolysis (PIP) process. The effects of pyrolysis temperature and SiC-filler content on microstructures and properties of the composites were systematically studied. The results show that the failure stress and fracture toughness increased with the increase of pyrolysis temperature. SiC filler of sub-micron scale infiltrated into the composites increased the mechanical properties. As a result, for the finally fabricated composite infiltrated with a slurry containing 40 wt.% SiC filler, the failure stress was doubled compared to that without SiC filler addition, and the fracture toughness reached ≈10 MPa m1/2. 相似文献
16.
《Journal of the European Ceramic Society》2022,42(13):5343-5354
In order to overcome challenges typically encountered during additive manufacturing of ceramics via the polymer precursor route, a novel polymer-derived SiOC/SiC composite system suitable for advanced geometric designs achievable by lithography-based ceramic manufacturing was established. The photoreactive resin system filled with 20 wt% SiC exhibits suitable viscosity characteristics, adequate stability against sedimentation, and a fast photocuring behavior. After printing and pyrolytic conversion, SiC particulates were well-dispersed within the polymer-derived SiOC matrix. A direct comparison with the unfilled polysiloxane-based resin system showed that the addition of particulate SiC increases handleability, reduces shrinkage, and significantly increases critical wall thicknesses up to 5 mm. The biaxial Ball-on-Three-Balls testing methodology yielded a characteristic strength of 325 MPa for SiOC/SiC composites. The results highlight the high potential of particle-filled preceramic polymer systems toward the fabrication of high-performance SiC-based materials by lithography-based additive manufacturing. 相似文献
17.
18.
《Ceramics International》2020,46(11):18785-18790
Silicon carbide (SiC) ceramic is the most prospective candidate material for space-based lightweight optical mirror. Stereolithography 3D printing has been reported to fabricate many kinds of ceramics, showing great potential for fabricating lightweight SiC ceramic optical mirror. In this paper, SiC ceramic was fabricated using stereolithography 3D printing combined with polymer burn-out, pre-sintering, and precursor infiltration and pyrolysis (PIP). The relative density, flexural strength, and microstructure during each step were investigated. The as-prepared lightweight SiC ceramic optical mirror exhibited high accuracy and high quality. Finally, it was proved that stereolithography 3D printing has a great potential for lightweight SiC ceramic optical mirror fabrication. 相似文献
19.
Hehao Chen Xiaofeng Wang Fengdan Xue Yujuan Huang Kechao Zhou Dou Zhang 《Journal of the European Ceramic Society》2018,38(16):5294-5300
3D structured SiC ceramics with varying feature sizes (100–400?μm) were achieved by direct ink writing of polycarbosilane (PCS)/n-hexane solution. The rheological properties of the PCS solution and printing parameters were tailored for optimum writing behaviour. The integrity and clear surface of the filaments indicated the printing ability of forming the self-supporting features along with the rapid evaporation of solvent. As-printed 3D structured PCS was processed by oxidative crosslinking and pyrolysis and converted to SiC ceramic. Although strong shrinkage occurred during the pyrolysis, SiC ceramic maintained the original 3D structure. Both proper viscoelasticity of printable solutions and the homogeneous shrinkage in the pyrolysis determine the integrity and feature characteristic of 3D structured SiC using direct ink writing preceramic polymer. 相似文献
20.
《Ceramics International》2017,43(14):11289-11295
Surfaces with superwetting capabilities can be used for corrosion protection, self-cleaning and bio-fouling protection amongst other applications. In this work, we present a method to produce a SiC coating with an almost superhydrophobic behavior exhibiting water contact angles of 145±3°. Ceramic coatings were produced by the pyrolysis of polycarbosilane as a preceramic precursor of SiC. Aluminum and carbon powders were used as active and passive fillers to compensate for the volume shrinkage of polycarbosilane during pyrolysis. The effects of particle size (Al particles ranging from 0.8 to 10 µm) and concentration 10–30% wt.) C and Al of both fillers were studied to produce defect-free ceramic coatings. We have observed that the fillers used not only affected the microstructure but also the surface roughness. We show that the addition of carbon fillers can increase the water contact angle of the ceramic from 42° up to 141°. The combination of carbon and aluminum fillers resulted in water contact angles up to 145°. 相似文献