SBIR Phase II: Process Control of Physical Property Variation in Vapor-Grown Carbon Fibers

小行星9623818 这个小型企业创新研究第二阶段项目将完善珠状纤维的CVD加工窗口，并开发无锯齿纤维的窗口。 由此产生的产品将用于制造各种复合材料，然后将相对于其正常的锯齿状纤维对应物进行测试。无褶皱纤维有望赋予其复合材料更好和更可靠的热传输和电传输性能。 珠状形态预期给予复合材料改进的机械增强，具有减少的裂纹扩展，以及由于其与基质物理互锁而不是化学键合的能力而在基质选择中具有更大的灵活性。本研究旨在确定控制气相生长碳纤维（VGCF）形态的制造工艺变量。 以前的研究表明，单个纤维的性能取决于它们表现出的一种称为锯齿的形态特征的程度。 此外，已经表明，通过在制造过程中进行某些修改，可以增加褶皱的严重程度。 在极端情况下，轻微的细锯齿让位于一种新颖的形态，具有明确的珠子，沿着沿着纤维的长度分散。 正在开发的VGCF形态将机械增强复合材料，并提供改进的热和电性能。 这种复合材料将用于汽车和航空航天工业，它们的低密度使它们具有非常高的重量调整品质因数。 它们也将用于电子工业。 该纤维也正在研究专门用于低摩擦轴承，并作为轮胎橡胶的增强材料。

9623818 Jacobsen This Small Business Innovation Research Phase II project will refine the CVD processing window for beaded fiber, and develop the window for crenulation free fiber. The resulting products will be used to fabricate various composites, which will then be tested relative to their normal crenulated fiber counterparts. Crenulation-free fiber is expected to impart improved and more reliable thermal and electrical transport properties to its composites. The beaded morphology is expected to give composites improved mechanical reinforcement, with reduced crack propagation, and greater flexibility in matrix choice due to its ability to physically interlock, rather than chemically bond, with a matrix. This research effort seeks to define manufacturing process variables for the control of vapor-grown carbon fiber (VGCF) morphology. Previous efforts demonstrated that the properties of individual fibers depend on the degree to which they exhibit a morphological feature called crenulation. Further, it has been shown that the severity of crenulation can be increased by certain modifications in the manufacturing process. In the extreme, mild crenulations give way to a novel morphology with well-defined beads, scattered along the fiber's length. The VGCF morphologies under development would mechanically reinforce composites, and provide improved thermal and electrical properties. Such composites would be employed in the automotive and aerospace industries, where their low densities give them a very high weight adjusted figure of merit. They would also be used in the electronics industry. The fiber is also being studied specifically for use in low-friction bearings, and as a reinforcement to tire rubber.