GRAiL

增材制造AM用于为广泛的市场（AppA）构建各种材料（特别是塑料和金属）的物理模型、原型、图案和生产部件。数字格式的组件被渲染成薄薄的水平截面，并使用各种技术（例如选择性激光烧结（SLS）， vatphotopolyisation，材料挤压和粉末床熔融）逐层添加材料来构建组件。SLS是在1984年开发的，它利用激光将金属层或聚合粉末相互熔化（AppA），自专利到期以来，这些机器的价格和可用性急剧下降，进一步刺激了需求。最初，聚合物SLS系统使用具有宽熔点的无定形聚合物（ABS），但今天几乎所有聚合物SLS系统都使用具有高熔点的结晶聚合物（通常是尼龙PA12），并且粉末是熔化的。不幸的是，与传统的挤出材料相比，SLS聚合物的性能降低了。纤维填料可以提高尼龙的韧性，但尼龙必须复合，然后冷冻或铣削，在粉末上产生角状表面，这限制了其流动特性。快速粉末有一个专有的工艺，沉淀的球形粉末可以涂上各种填充材料（包括纳米填料），特别是石墨烯，这是聚合物纳米复合材料的理想填料，可以改善其机械性能。我们建议证明生产一系列具有良好流动特性的PA12 -石墨烯纳米复合粉末的概念，当在SLS机器中熔化或烧结时，其性能可与挤压的PA12相媲美，从而实现SLS生产成品组件。

Additive Manufacturing AM is used to build physical models, prototypes, patterns, andproduction parts in a wide variety of materials (in particular plastic, and metals) for a widerange of markets (AppA). Components in digital format are rendered into thin horizontalsections and using various techniques (e.g. Selective Laser Sintering (SLS), VatPhotopolymerisation, Material Extrusion and Powder Bed Fusion) material is added layer bylayer to build the component. SLS which utilises lasers to melt layers of metal or polymerpowder on to each other (AppA) was developed in 1984 and since the patents expired and theprice and availability of these machines has dropped dramatically, further stimulatingdemand. Initially, polymer SLS systems used amorphous polymers (ABS) with a broadmelting range but today almost all polymer SLS systems use crystalline polymers with a sharpmelting point (typically Nylon PA12) and the powder is melted. Unfortunately SLS polymerproperties are diminished compared to conventional extruded material.Fibrous fillers can improve toughness but the nylon has to be compounded and then cryogroundor milled producing angular surfaces on the powder which restrict its flowcharacteristics. Rapid Powders has a proprietary process whereby precipitated sphericalpowders can be coated with a wide range of filler materials (including nano-fillers) and inparticular Graphene which is a desirable filler for polymer nanocomposites and improves theirmechanical properties. We propose to prove the concept of the production of a range of PA12graphene nanocomposite powders with good flow characteristics that when melted or sinteredin a SLS machine have improved properties comparable to extruded PA12 enabling the SLSproduction of finished components.