PDF(Pubmed)
Abstract：
Laser sintering (LS) of polyamide 12 (PA12) is increasingly being adopted for industrial production of end-use parts, yet the complexity of this process coupled with the lack of organized, rigorous, publicly available process-structure-physical property datasets exposes manufacturers and customers to risks of unacceptably poor part quality and high costs. Although an extensive scientific literature has been developed to address some of these concerns, results are distributed among numerous reports based on different machines, materials, process parameters, and users. In this study, a single commercially important LS PA12 feedstock has been processed along four build dimensions of a modern production LS machine, characterized by a wide range of physical techniques, and compared to the same material formed by conventional melt processing. Results are discussed in the context of the literature, offering novel insights including distributions of particle size and shape, localization of semicrystalline phase changes due to LS processing, effect of chemical aging on melt viscosity, porosity orientation relative to LS build axes, and microstructural effects on tensile properties and failure mechanisms. The resulting datasets will be made publicly available to modelers and practitioners for the purpose of improving certifiability and repeatability of end-use parts manufactured by LS.
摘要：
聚酰胺12（PA12）的激光烧结（LS）越来越多地用于最终用途零件的工业生产，然而，这个过程的复杂性加上缺乏有组织的，严谨,公开可用的过程-结构-物理特性数据集使制造商和客户面临不可接受的不良零件质量和高成本的风险。尽管已经开发了大量的科学文献来解决其中的一些问题，结果分布在基于不同机器的众多报告中，材料,工艺参数,和用户。在这项研究中,单个商业上重要的LSPA12原料已经沿着现代生产LS机器的四个构建尺寸进行了处理，以广泛的物理技术为特征，并与通过常规熔融加工形成的相同材料进行比较。结果在文献中讨论，提供新颖的见解，包括粒度和形状的分布，由于LS加工而导致的半晶相变化的局部化，化学老化对熔体粘度的影响，相对于LS构建轴的孔隙度取向，以及微观结构对拉伸性能和破坏机理的影响。由此产生的数据集将公开提供给建模者和从业者，以提高LS制造的最终使用零件的可验证性和可重复性。
