An Interdisciplinary Approach to Improved Material Properties of Layered Manufacturing Functional Parts

物理原型在一种称为“分层制造”或“固体自由成型制造”（SFF）的概念的帮助下得到了普及。SFF的主要优点主要来自于其创建物理模型的能力，而不管形状的复杂性如何。 然而，当今社会可用的大多数SFF工艺生产的是“触感”部件，而不是可用于工程应用的“功能”部件。 虽然许多新的部分可以从这些过程中，残余应力和材料性能的各向异性限制了目前的做法的适用性。残余应力是以分层方式制造的部件的特征，可导致变形、翘曲和分层。 为了解决这些问题，来自斯坦福大学和加州大学戴维斯分校的研究人员正在联合探索方法，以（1）降低金属和非金属材料分层沉积期间的残余应力水平，以及（2）通过优化沉积图案和合成新的复合材料来生产具有增强的微观结构的部件，该微观结构具有高机械强度和良好的耐磨性。预计本研究将产生以下结果： 更深入地了解成分成分和工艺变量对材料性能和材料沉积特性的关系。 合成具有低热膨胀系数（CTE）基体和增强材料性能的材料复合材料。 材料沉积策略的发展，最大限度地减少热梯度和优化微观结构形态。 集成建模和处理工作，以改进零件分解和分层策略，从而实现最佳零件设计和制造。

Physical prototyping has gained popularity with the help of a concept called "layered manufacturing" or"solid free form fabrication" (SFF). The main benefits from SFF are mostly derived from its ability to create physical models regardless of shape complexity. However, the majority of SFF processes available to the community today, produce "touch and feel" parts rather than 'functional' components that can be used for engineering applications. Although many novel parts can be made from these processes, residual stresses and anisotropy of material properties limit the applicability of current practices. Residual stresses, a characteristic feature of components made in a layerwise fashion, can cause distortion, warping, and delamination. In response to these problems researchers from Stanford and the University of California-Davis are jointly exploring methods to (1) reduce residual stress levels during layered deposition of metallic and non-metallic materials and to (2) produce parts with enhanced microstructures with high mechanical strength and good wear resistance by optimizing the deposition patterns and synthesizing new composite materials. The following results are anticipated from the present research: The development of a deeper understanding of the relationship of compositional constituents and process variables upon material properties and material deposition characteristics. The synthesis of material composites with low coefficients of thermal expansion (CTE) matrix and enhanced material properties. The development of material deposition strategies which minimize thermal gradients and optimize microstructural morphology. The integration of modeling and processing efforts to improve part decomposition and layering strategies for optimal part design and fabrication.