Artie McFerrin Department of Chemical Engineering , Texas A&M University , College Station , Texas 77843 , United States.
Department of Electrical and Computer Engineering , Texas Tech University , Lubbock , Texas 79409 , United States.
ACS Appl Mater Interfaces. 2019 Dec 11;11(49):46132-46139. doi: 10.1021/acsami.9b14971. Epub 2019 Dec 2.
Silicon carbide (SiC) fibers are widely used as a reinforcement in ceramic matrix composites due to their high mechanical strength and superior thermal resistance. Here, we investigate the rapid radio frequency (RF) heating response of two types of SiC fibers (Hi-Nicalon and Sylramic) in the 1-200 MHz frequency range. Hi-Nicalon fibers exhibit a surprisingly rapid RF heating response of 240 °C/s in the perpendicular orientation, and this property could be exploited for oven-free and noncontact processing of composites with SiC fibers. The presence of excess carbon on the surface of Hi-Nicalon fibers is most likely responsible for the RF heating response and significantly higher temperatures in the parallel as compared to perpendicular alignment of fibers to the electric field. The RF heating response of Hi-Nicalon SiC fibers was utilized to heat preceramic polymers (polycarbosilanes) infiltrated in SiC fibers and cure them to ceramic matrix composites (CMCs) using RF applicators. A noncontact RF heating setup to pyrolyze the precursor polymers under inert conditions and make SiC/SiC composites is also developed.
碳化硅（SiC）纤维由于其高强度和优异的耐热性而被广泛用作陶瓷基复合材料的增强体。在这里，我们研究了两种 SiC 纤维（Hi-Nicalon 和 Sylramic）在 1-200MHz 频率范围内的快速射频（RF）加热响应。Hi-Nicalon 纤维在垂直方向上表现出惊人的快速 RF 加热响应，加热速率为 240°C/s，这一特性可用于 SiC 纤维复合材料的无烤箱和非接触式加工。Hi-Nicalon 纤维表面存在过量的碳，很可能是导致 RF 加热响应和纤维平行于电场时比垂直于电场时温度显著升高的原因。Hi-Nicalon SiC 纤维的 RF 加热响应被用于加热浸渍在 SiC 纤维中的先驱体聚合物（聚碳硅烷），并使用 RF 应用器将其固化为陶瓷基复合材料（CMC）。还开发了一种非接触式 RF 加热装置，用于在惰性条件下热解先驱体聚合物，制造 SiC/SiC 复合材料。
