Optimizing the Properties of Polymers and Composites Made by Additive Manufacturing

拟议的研究计划集中在使用数字增材制造制造的材料的加工，结构和机械性能之间的关系的分析和建模。术语“增材制造”，也称为“3D打印”，描述了许多不同的工艺，其中通过沉积非常薄的材料层来构造固体部件，所述材料层熔合或结合到先前沉积的层的材料。商业机器已经被制造成以这种方式存款各种材料：聚合物、金属、陶瓷、复合材料，甚至生物相容的人体组织支架。在所有情况下，各个层（最终是整个零件）都直接从数字文件渲染。这允许在零件的概念和实际三维对象的创建之间非常快速的转换。因此，增材制造也被广泛称为“快速原型”。 对于非功能性原型，材料特性通常不是很重要，但目前从增材原型到增材制造的过渡表明，对制造参数，材料和组件完整性之间关系的理解将成为未来十年的关键问题。 熔丝制造是关键的增材技术之一，并且涉及热塑性塑料的薄熔融丝的逐层沉积。已知所得的机械性能取决于材料、温度、打印速度、填充图案和孔隙率。我们计划启动一项研究计划，以使用各种技术对FDM部件和断裂面进行结构分析为中心。 我们将发现结构和最终性能之间的关系，并就数字印刷材料的最佳结构提出建议。 我们还将了解加工条件如何控制结构，以便我们能够找到最佳方法来制作可用于结构应用的零件的低成本快速打印。

The proposed program of research centers on the analysis and modeling of the relationship between processing, structure, and mechanical properties of materials made using digital additive manufacturing. The term “additive manufacturing”, also known as “3D printing”, describes a number of different processes in which a solid component is constructed by depositing very thin layers of material that fuse or bond to the material of the previously deposited layer. Commercial machines have been made to deposit a variety of materials in this way: polymers, metals, ceramics, composites, and even biocompatible human tissue scaffolds. In all cases, the individual layers (and eventually the entire part) are rendered directly from a digital file. This allows for a very quick turnaround between the conception of a part and the creation of the actual three-dimensional object. Hence additive manufacturing has also been widely referred to as “rapid prototyping”. For a non-functional prototype, material properties are often not very important, however the current transition from additive prototyping to additive manufacturing suggests that an understanding of the relationship between manufacturing parameters, materials, and component integrity will become a critical issue over the next decade. Fused filament fabrication is one of the key additive technologies, and involves the deposition of thin molten filaments of thermoplastic, layer by layer. The resultant mechanical properties are known to be dependent on material, temperature, print speed, fill pattern, and porosity. We are planning to initiate a research program centered on the structural analysis of FDM parts and fracture surfaces using a variety of techniques.  We will discover relationships between the structure and final properties, and will make recommendations about the optimal structures for digitally printed materials.  We will also learn how the processing conditions control structure, so that we can find best way to make low-cost rapid prints of parts that can be used in structural applications.