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

这个小型企业创新研究第一阶段项目将开发3D打印连续纤维增强陶瓷基复合材料(CMC)组件的工艺，用于涡轮和内燃机、高超声速飞行器和卫星。CMCS目前的市场规模为25亿美元，预计未来10年将增长两倍。通过3D打印生产CMCS的能力将使其能够在当前应用中实现卓越的设计，并使其能够在更多组件中使用，这些组件目前受到Inconel和Invar等高温合金较高密度和较低温度能力的限制。开发这一制造工艺将使更多的基础材料研究成为新的CMC组合物的低成本试验台，因为不需要模具，周转时间要快得多。这还将使工程师能够以更快的设计周期开发更优化的系统。这一能力将导致涡轮和内燃机效率的提高，从而大幅提高燃料效率，降低成本和对环境的影响。最后，3D打印CMCS的能力将极大地提高高温部件的几何复杂性，这将使下一代高超声速飞行器成为可能，支持国防。本项目的智力优势在于建立了基于3D打印的CMCS制造新工艺。熔体渗透是一种低成本的制造CMCS的方法，它首先将聚合物基复合材料热解，然后用熔融的金属渗透。基质通常是酚醛热固性树脂，但高温热塑性塑料最近已被证明适用于简单的优惠券。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体。由于热塑性塑料熔化，将在热解步骤中实施支撑材料，这将有效地保持部件的几何形状。此外，将实施一种新的工艺，即在热解之后而不是在形成聚合物复合材料之前在纤维上生长氮化硼界面层，因为印刷过程中的紧角可能会损坏界面层。最后，将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。该项目将展示这种界面的有效性，提高了弯曲强度和韧性，以及形成几何复杂的CMC的能力，这些CMC即使不是不可能用其他方法制造也是极其困难的。这两个里程碑将使我们能够开始为商业应用中的客户开发部件。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.