Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 2000°C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. From the processing point of view, preceramic polymers have been used as reactive binders to produce technical ceramics, they have been manipulated to allow for the formation of ordered pores in the meso-range, they have been tested for joining advanced ceramic components, and have been processed into bulk or macroporous components. Consequently, possible fields of applications of PDCs have been extended significantly by the recent research and development activities. Several key engineering fields suitable for application of PDCs include high-temperature-resistant materials (energy materials, automotive, aerospace, etc.), hard materials, chemical engineering (catalyst support, food- and biotechnology, etc.), or functional materials in electrical engineering as well as in micro/nanoelectronics. The science and technological development of PDCs are highly interdisciplinary, at the forefront of micro- and nanoscience and technology, with expertise provided by chemists, physicists, mineralogists, and materials scientists, and engineers. Moreover, several specialized industries have already commercialized components based on PDCs, and the production and availability of the precursors used has dramatically increased over the past few years. In this feature article, we highlight the following scientific issues related to advanced PDCs research: (1) General synthesis procedures to produce silicon-based preceramic polymers.
(2) Special microstructural features of PDCs.
(3) Unusual materials properties of PDCs, that are related to their unique nanosized microstructure that makes preceramic polymers of great and topical interest to researchers across a wide spectrum of disciplines.
(4) Processing strategies to fabricate ceramic components from preceramic polymers.
(5) Discussion and presentation of several examples of possible real-life applications that take advantage of the special characteristics of preceramic polymers. Note: In the past, a wide range of specialized international symposia have been devoted to PDCs, in particular organized by the American Ceramic Society, the European Materials Society, and the Materials Research Society. Most of the reviews available on PDCs are either not up to date or deal with only a subset of preceramic polymers and ceramics (e.g., silazanes to produce SiCN-based ceramics). Thus, this review is focused on a large number of novel data and developments, and contains materials from the literature but also from sources that are not widely available.

Polymer-Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Carbon/carbon (C/C) composites are considered as one of the most promising materials in structural applications owing to their excellent mechanical properties at high temperature. However, C/C composites are susceptible to high-temperature oxidation. Matrix modification and coating technology with ultra-high temperature ceramics (UHTCs) have proved to be highly effective to improve the oxidation and ablation resistance of C/C composites. In this paper, recent advances in oxidation and ablation resistance of C/C composites were firstly reviewed, with attention to oxidation and ablation properties of C/C composites coated or modified with UHTCs. Then, several new methods in improving oxidation and ablation resistance were discussed, such as by using nanostructures to toughen UHTCs coatings or carbon matrix and the combination of matrix modification and coating technology. In addition, relevant ablation tests with scaled models were also briefly introduced. Finally, some open problems and future challenges were highlighted in the development and application of these materials.

Advances in oxidation and ablation resistance of high and ultra-high temperature ceramics modified or coated carbon/carbon composites

The fate and role of in situ formed carbon in polymer-derived ceramics

Fabrication of 2D C/ZrC–SiC composite and its structural evolution under high-temperature treatment up to 1800 °C

Digital light processing technology (DLP) is an effective additive manufacturing method to fabricate ceramic components with high precision and complicated structure. Here, a novel strategy to prepare chopped carbon fibers (Cf)/SiC ceramic composites through stereolithography Cf combined with liquid silicon infiltration is presented. The photosensitive suspension including Cf was prepared and Cf preforms with convoluted geometrical shapes were manufactured by DLP technology. The 3D-architectured bodies possessed high printing stableness and accuracy with the forming deviation of less than 5%. Moreover, the tightly bonded adjacent layers can contribute to the synergistic effect from curing adhesion of photosensitive resin and crisscrossed pinning of chopped carbon fibers. As-prepared components after liquid silicon infiltration were dense and exhibited maximum flexural strength of 262.6 MPa. This strategy demonstrates a promising prospect and tantalizing possibility to fabricate SiC ceramic composites with complex shapes and structures.

Stereolithography-based additive manufacturing of lightweight and high-strength Cf/SiC ceramics

Manufacturing 2D carbon-fiber-reinforced SiC matrix composites by slurry infiltration and PIP process

Effect of in situ grown SiC nanowires on microstructure and mechanical properties of C/SiC composites

2.5D SiCf/SiC composites were produced by a modified polymer infiltration and pyrolysis process. Fine Al and SiC powders were first infiltrated into large inter-bundle pores. During pyrolytic decomposition of the polymer, the active Al filler reacts with small carbon-bearing polymer fragments, and reactive nitrogen atmosphere to form new phases of carbide or nitride. The volume expansion compensates for polymer shrinkage to a certain degree. The microstructural evolution and mechanical performances were characterized. The result indicates that the addition of Al fillers has significant influence on the mechanical properties of the composites. For the composite with Al loading, a proportional-limit stress of 380 MPa and a maximum stress of 441 MPa are achieved.

Ming Yuan

Papers

Manufacturing 2D carbon-fiber-reinforced SiC matrix composites by slurry infiltration and PIP process

Effect of in situ grown SiC nanowires on microstructure and mechanical properties of C/SiC composites

Fabricating 2.5d SiCf/SiC composite using polycarbosilane/SiC/Al mixture for matrix derivation

The fabrication of 2D Cf/SiC composite by a modified PIP process using active Al powders as active filler

Correlation of PyC/SiC interphase to the mechanical properties of 3D HTA C/SiC composites fabricated by polymer infiltration and pyrolysis