SBIR Phase I: Novel Extrusion System for Additive Manufacturing of Engineered Lattice Structures

该小型企业创新研究（SBIR）第一阶段项目的更广泛的影响/商业潜力是支持在航空航天和国防工业的大幅面增材制造中使用可持续材料，更坚固的零件和节省材料。该技术有可能减少打印时间和能源消耗。它还可以以目前制造业无法达到的规模打印复杂的几何形状。该项目的智力价值在于解决客户在大幅面增材制造行业面临的两大技术挑战：Z方向的低强度和高表面孔隙率。该项目正在开发两种创新解决方案来应对这些技术挑战。第一个创新是使用多个独立铰接的喷嘴通过非平面打印方法打印零件。在概念验证实验中，这项创新已经成功地实现了非平面光纤对准。它显示了通过在加载方向上定制纤维排列来提高Z方向上的强度的潜力。对于第二项创新，将开发一种喷嘴设计，通过喷嘴加热打印材料。该技术的原型已经显示出ASTM D-638拉伸测试样品的强度增加了30-40%。据推测，强度的提高是由于孔隙率的降低、层间结合的改善和聚合物的缠结，这可以解决大幅面增材制造的第二大挑战。该奖项反映了NSF的法定使命，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。

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to support the use of sustainable materials, stronger parts, and material savings in Large Format Additive Manufacturing for the Aerospace and Defense Industry. The technology has the potential to reduce printing time and energy consumption. It could also enable the printing of complex geometries at a scale not currently accessible in the manufacturing industry. The intellectual merit of this project is to address the two biggest technical challenges customers face in the Large Format Additive Manufacturing industry: low-strength in the Z-direction, and high surface porosity. This project is developing two innovative solutions to address these technical challenges. The first innovation is using multiple independently articulated nozzles to print a part through a non-planar printing approach. During proof-of-concept experiments, this innovation has shown success for non-planar fiber alignment. It shows the potential to improve strength in the Z-direction, by custom fiber alignment in the direction of loading. For the second innovation, a nozzle design will be developed to heat printed material through the nozzles. A prototype for this technology has already shown a 30-40% increase in strength for ASTM D-638 tensile test specimens. It is hypothesized that the increase in strength is due to decrease in porosity, improved layer bonding, and polymer entanglement, which can solve the second big challenge for Large Format Additive Manufacturing.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.