Understanding Physical Property Variation in Vapor-Grown Carbon Fibers

这个小型企业创新研究第一阶段项目旨在识别和消除一种名为蒸气生长碳纤维(VGCF)的新型石墨化纤维的缺陷形成来源。VGCF具有等同于或大大超过其他类型的碳纤维以及金属的工程性能。此外，VGCF可以通过简单、快速和廉价的化学气相沉积(CVD)工艺生产，因此有可能极大地降低高性能碳纤维增强材料的成本。然而，VGCF的用途目前受到批次模式生产的限制，这种生产模式在批次内以及批次之间的物理性质都有很大的差异。因此，纤维的可预测性不足以应用于关键的工程应用。拟议的研究工作将寻求确定纤维质量差异的来源，并通过在CVD过程中的改进来消除这些差异。具体地说，这项工作将调查纤维特性的变化和纤维的一种特殊形态特征(称为褶皱)的出现之间的关系，然后确定其仔细控制将最好地缩小纤维特性值范围的工艺变量。优化这些变量和开发技术以更好地控制它们，特别是在大批量生产期间，将是相关第二阶段工作的预期重点。

This Small Business Innovation Research Phase I project seeks to identify and eliminate the sources of defect formation in a novel graphitic fiber called Vapor Grown Carbon Fiber (VGCF). VGCF possesses engineering properties that equal or greatly exceed other types of carbon fiber, as well as metals. Additionally, VGCF can be produced in a simple, rapid and inexpensive chemical vapor deposition (CVD) process, thus holding potential to greatly reduce the cost of high performance carbon fiber reinforcements. However, the usefulness of VGCF is currently limited by batch-mode production which yields a large variation in physical properties both within the batch, as well as between batches. Consequently, the fibers are not sufficiently predictable to commit to critical engineering applications. The proposed research effort will seek to identify the source of variations in fiber quality, and to eliminate the variations through refinements in the CVD process. Specifically, this effort will investigate the relationship between variation in fiber properties and the occurrence of a particular morphological feature of the fibers called crenulations, and then determine those process variables whose careful control will best narrow the range of values of the fiber properties. Optimization of these variables and development of techniques to better control them, especially during higher volume production, will be the intended focus of the associated Phase II effort.