SBIR Phase I: High-Efficiency Closed-System Chemical Vapor Infiltration (CVI) Process

这个小型企业创新研究(SBIR)第一阶段项目将展示一种新的、高效的纤维预制棒渗透/致密工艺的可行性。这种方法被称为闭式系统化学气相渗透法(CSCVI)，与传统的化学气相渗透法相比具有几个优点。原材料的使用效率很高，未反应的原材料很容易回收利用，从而将材料成本降至最低。因为这个过程是在一个封闭的系统中进行的，所以没有废物流，而且只使用了极少量的危险材料。废流的显著减少转化为废物处理成本的极大降低。该项目将专门针对纤维增强陶瓷基复合材料(CMC)的制造。通过高效率地运行和最大限度地减少废流，仅基于材料成本，预计每个部件的成本将降低约45%。此外，由于废流减少了数量级，废物处理所需的资本设备将大大减少。基本上，目前使用传统CVI的任何系统都可以从CSCVI的应用中受益。CSCVI的成功示范有望提高陶瓷基复合材料的经济性。CMC得益于碳/碳化硅(C/碳化硅)和碳化硅/碳化硅材料的成功。然而，这些材料的成本相当高，任何能够显著降低成本的技术都有望找到一个巨大的商业市场。

This Small Business Innovation Research (SBIR) Phase I project will demonstrate the feasibility of a novel, high-efficiency process for the infiltration/densification of fiber preforms. This method, designated closed-system chemical vapor infiltration (CSCVI), offers several advantages over conventional CVI. Raw material is used in a highly efficient manner, and unreacted raw material is easily recycled for future use, thereby minimizing materials costs. Because the process takes place inside a sealed system, there is no waste stream, and only extremely small amounts of hazardous material are used. The dramatic reduction in the waste stream translates into greatly reduced costs for waste treatment. This project will specifically address the manufacture of fiber-reinforced ceramic matrix composites (CMCs). By operating at high efficiencies and minimizing the waste stream, it is expected that the cost reduction per part will be about 45%, based on material costs alone. Furthermore, because the waste stream is reduced by orders of magnitude, capital equipment required for waste treatment will be greatly reduced. Essentially any system currently utilizing conventional CVI can benefit from the application of CSCVI. A successful demonstration of CSCVI is expected to improve the economics of ceramic matrix composites. CMCs have benefitted from the success of carbon/silicon carbide (C/SiC) and SiC/SiC materials. The cost of these materials is quite high, however, and any technique that will significantly reduce their cost is expected to find a large commercial market.