SBIR Phase I: Continuous Fiber Ceramic Matrix Composite 3D Printing

这个小企业创新研究第一阶段项目将开发用于涡轮和内燃机、高超音速飞行器和卫星的3D打印连续纤维增强陶瓷基复合材料（CMC）组件的工艺。cmc目前是一个25亿美元的市场，预计未来10年将增长两倍。使用3D打印生产cmc的能力将在当前的应用中实现卓越的设计，并使其能够在更多的组件中使用，这些组件目前受到高温合金（如Inconel和Invar）的高密度和低温能力的限制。由于不需要模具，周转时间也快得多，因此开发这种制造工艺将作为新CMC组合物的低成本测试平台，从而使更多的基础材料研究成为可能。这也将使工程师能够以更快的设计周期开发出更优化的系统。这种能力将提高涡轮和内燃机的效率，从而大幅提高燃油效率，降低成本和对环境的影响。最后，3D打印cmc的能力将大大提高高温部件的几何复杂性，这将使下一代高超音速飞行器成为可能，支持国防。该项目的智力优势在于建立了一种基于3D打印的新型cmc制造工艺。熔融渗透是一种低成本的生产cmc的方法，该方法首先将聚合物基复合材料进行热解，然后用熔融金属渗透。基体通常是酚醛热固性，但高温热塑性塑料最近被证明是可行的简单的优惠券。本项目将采用5轴连续纤维增强高温热塑性复合材料作为绿色主体。由于热塑性塑料熔化，支撑材料将在热解步骤中实施，这有效地保持了零件的几何形状。此外，由于打印过程中的拐角可能会损坏界面层，因此将在热解后而不是在聚合物复合材料形成之前在纤维上生长氮化硼界面层的新工艺将被实施。最后，尝试用更大弯曲半径的碳化硅纤维代替碳纤维进行3D打印。该项目将展示该界面的有效性，提高了弯曲强度和韧性，并能够形成几何上非常复杂的cmc，这是其他方法很难做到的，如果不是不可能的话。这两个里程碑将为开始在商业应用中为客户开发零件开辟一条道路。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Small Business Innovation Research Phase I project will develop the process to 3D print continuous fiber reinforced ceramic matrix composite (CMC) components for turbine and combustion engines, hypersonic vehicles, and satellites. CMCs are currently a $2.5b market that is expected to triple over the next decade. The ability to produce CMCs with 3D printing will enable superior designs in current applications, as well as enabling their use in a greater number of components that are currently limited by the higher density and lower temperature capabilities of superalloys such as Inconel and Invar. Developing this manufacturing process will enable more basic materials research by serving as a lower cost testbed for new CMC compositions since a mold is not required and turnaround times are much faster. This will also allow engineers to develop more optimized systems with a faster design cycle. This capability will result in efficiency increases in turbine and combustion engines for substantial improvements in fuel efficiency, reducing costs and environmental impact. Finally, the ability to 3D print CMCs will vastly improve geometric complexity of high temperature components, which will enable the next generation of hypersonic vehicles, supporting national defense.The intellectual merit of this project is in establishing a novel manufacturing process for CMCs based on 3D printing. Melt infiltration is a low cost method to produce CMCs, which starts with a polymer matrix composite that is pyrolyzed, and then infiltrated with a molten metal. The matrix is usually a phenolic thermoset, but high temperature thermoplastics have recently been proven viable for simple coupons. This project will use 5-axis continuous fiber reinforced high temperature thermoplastic composites as green bodies. Since thermoplastics melt, support materials will be implemented during the pyrolysis step, which are effective in retaining part geometry. Additionally, a novel process of growing a boron nitride interphase layer on the fibers after pyrolysis instead of prior to forming the polymer composite will be implemented since tight corners during printing might damage an interphase layer. Finally, 3D printing with larger bend radius silicon carbide fibers instead of carbon fibers will be attempted. This project will demonstrate the effectiveness of this interphase with improved flexural strength and toughness, and the ability to form geometrically complex CMCs that are extremely difficult, if not impossible, to make with other methods. These two milestones will enable a path to begin developing parts for customers in commercial applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.