China
Africa
Explore chapters and articles related to this topic
Progress of Ceramic Fibers
Published in Toshihiro Ishikawa, Ceramic Fibers and Their Applications, 2019
Polymer-derived ceramic fibers were synthesized making the best use of a shape-forming ability of polymers. In this case, polymers, which can be converted into ceramics by heat treatment at high temperatures, were used as precursor materials. The precursor materials are also called preceramic polymers, which were proposed in the 1960s as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics. The conversion process ranged from polymer-to ceramic-enabled technological breakthroughs in the field of ceramics. That is to say, using the preceramic polymers, the developments of thin ceramic fibers, environmental barrier coatings, and excellent stabilities at ultrahigh temperatures (up to 2000 °C) could be enabled. And, process technologies concerning decomposition, phase separation, crystallization, and sintering were proposed and developed. Furthermore, using fundamental properties of the precursor polymers, unique morphologies, and excellent functions have been developed. In this section, several types of polymer-derived ceramic fibers, especially Si-based ceramic fibers, are described.
Additive Manufacturing of Ceramics
Published in Amit Bandyopadhyay, Susmita Bose, Additive Manufacturing, 2019
Susmita Bose, Naboneeta Sarkar, Sahar Vahabzadeh, Dongxu Ke, Amit Bandyopadhyay
Ti3SiC2-based ceramics were processed using a combination of 3DP and liquid silicon infiltration. TiC powder and dextrin were used as printing feedstock and binder, respectively. Liquid silicon filtration was performed in an Ar atmosphere at 1600°C–1700°C followed by annealing at 1400°C. The obtained Ti3SiC2-TiSi2-SiC composite at 1700°C demonstrated relatively high bending strength of 293 MPa and Vickers hardness of 7.2 GPa [109]. In another study, SiOC polymer derived ceramics have been processed using 3DP of a pre-ceramic polymer. In addition to the specific properties such as luminescence and piezoresistivity, PDCs also have unique oxidation resistance and thermomechanical properties. In this study, a polymethylsilsesquioxane pre-ceramic polymer powder (MK) was used. Two different approaches were applied to print the parts: (1) MK powder was mixed with isopropanol and zirconium acetylacetonate (ZrAcAc) was used as a catalyst. This mixture was used after drying as the base powder precursor and isopropanol was used as the printing media. (2) Tin-octoate (TinOc) was dissolved in 1-hexanol and hexyl acetate mixture and isopropanol was used as the printing media [110].
Ceramics: Processing, Properties, and Applications
Published in Noureddine Ramdani, Polymer and Ceramic Composite Materials, 2019
Polymer-derived ceramics (PDCs) present a new category of technical ceramics, especially in the ternary and multinary systems like SiCO, SiCN, Si(M)CO, and Si(M)CN (M = metal), prepared generally by the thermal treatment of suitable preceramic polymers in an inert or reactive atmosphere and under temperatures ranging from 800 to 1,500°C (Figure 2.5) [16]. They show two significant advantages. First, the ceramics resulting from polymeric precursors generally provide a chemical composition that cannot be affordable by other techniques. Second, the possibility of joining the shaping and synthesis of ceramics means that constituents can be designed at the precursor phase using conventional plastic-forming techniques, including spinning, blowing, injection-molding, warm pressing, and resin transfer molding, before they are converted into ceramics under heat treatments at temperatures exceeding 800°C.
Additive manufacturing of flexible polymer-derived ceramic matrix composites
Published in Virtual and Physical Prototyping, 2023
Jun Ou, Minzhong Huang, Yangyang Wu, Shengwu Huang, Jian Lu, Shanghua Wu
Polymer-derived ceramics (PDCs) are a class of ceramic materials that can be formed directly from precursors by pyrolysis, without the need for sintering (Colombo et al. 2010; Xia et al. 2020). For instance, polycarbosilane, polysiloxane, polysilazane, and polyborosilazane can be pyrolyzed to silicon carbide (SiC), silicon oxycarbide (SiOC), silicon carbon nitride (SiCN), and silicon boron carbon nitride (SiBCN), respectively. Moreover, the pyrolysis of PDCs is completed at relatively low temperatures (typically 800–1300°C) (He et al. 2020; Zanchetta et al. 2016), and PDCs are resistant to oxidation, creep, and phase separation at temperatures up to 1500°C and higher (Colombo et al. 2010; Zanchetta et al. 2016). Furthermore, preceramic polymers can be modified such that they can be converted to ceramic parts with the compositions and microstructures necessary to exhibit desired performances and functionalities (Riedel et al. 2006; Zhou et al. 2020). In particular, flexible preceramic polymer materials can be easily designed to meet the demand for 3D-printed and deformable green ceramic parts, which provides the opportunity to realise the 4D printing of deformable ceramic structures that can be stably transformed into various shapes.
3D printing of complex-shaped polymer-derived ceramics with enhanced structural retention
Published in Materials and Manufacturing Processes, 2022
Jian Liu, Shufeng Xiong, Hui Mei, Zhangwei Chen
In recent years, researchers have also focused on polymer-derived ceramics (PDCs) technique, which involves first preparing the preceramic polymers (PCPs) or precursor resin via chemical synthesis.[23,24] The good shaping ability of PCPs is used for processing and forming. This is followed by pyrolysis at high-temperature to obtain advanced ceramic parts that are difficult to manufacture via traditional solid-phase synthesis methods, such as SiC, SiCN, SiOC, SiBN, and various binary and polynary ceramics. PDC technique allows for the easy design and synthesis of molecular compositions and low-temperature ceramization because the raw material itself is a mixture of polymers. Hence, this overcomes the limitations of ceramic materials and has completely changed the preparation process of ceramics. The precursor materials are also particularly suitable for 3D printing, especially using digital light processing photo-curing method. In recent years, studies have combined PDCs with 3D printing technology, opening new avenues to use PDCs to produce high-end ceramics with complex structures.[3,8,25,26]
Solution based freeze cast polymer derived ceramics for isothermal wicking - relationship between pore structure and imbibition
Published in Science and Technology of Advanced Materials, 2019
Daniel Schumacher, Dawid Zimnik, Michaela Wilhelm, Michael Dreyer, Kurosch Rezwan
Compared to conventional ceramics such as Al2O3, TiO2 and mullite polymer-derived ceramics offer some advantages. Significantly reduced thermal conductivity ensures benefits in capillary transport at cryogenic conditions and lower pyrolysis/sintering temperatures provide advantages in terms of environment and costs [20]. Furthermore, incomplete decomposition of the organic groups at low pyrolysis temperatures results in the creation of micropores and allows for the adjustment of the surface characteristic, e.g. hydrophilicity. The unique adjustment of micropores and hydrophilicity by pyrolysis temperature enables additional possibilities to adapt the material to specific capillary transport applications. In contrast to conventional powder-based fabrication methods, preceramic polymers offer a great versatility in shaping techniques. Also, shaping methods assigned to polymers such as solution-based freeze-casting can be used [21].