Volumetric fusion of graphite-doped nylon 12 powder with radio frequency radiation
Volumetric fusion of graphite-doped nylon 12 powder with radio frequency radiation
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DOI：
10.1108/rpj-09-2020-0218
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发表时间：
2021-09
影响因子：
3.9
通讯作者：
J. Allison;J. Pearce;J. Beaman;C. Seepersad
中科院分区：
文献类型：
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作者：
J. Allison;J. Pearce;J. Beaman;C. Seepersad
用于粉末床熔融工艺的热塑性聚合物增材制造（AM）通常需要在沉积下一层之前将每一层熔融。本文的目的是提出一种体积AM方法，以深度穿透射频（RF）辐射的形式，以提高聚合物部件的加工速度和机械性能。设计/方法/方式-本研究的重点是证明含有聚酰胺（尼龙）12和石墨粉末的复合材料混合物的体积融合使用RF辐射作为唯一的能源，以建立一个体积AM热塑性聚合物的过程的可行性。阻抗谱被用来测量作为增加石墨含量的函数的混合物的介电性能，并确定渗滤极限。然后在连接到RF发生器的平行板电极室中测试混合物以测量不同石墨浓度的加热效率。在实验期间，监测掺杂混合物的表面温度。结果尼龙12的混合物中含有10%和60%之间的石墨重量的创建，和损耗角正切达到最大值为35%。通过在粉末床内形成熔融复合材料部件，显示了选择性RF加热。独创性/价值-一种新的体积AM热塑性聚合物的过程的可行性在这项研究中被证明，其中RF辐射被用来实现石墨掺杂的尼龙粉末中的融合。
Purpose Additive manufacturing (AM) of thermoplastic polymers for powder bed fusion processes typically requires each layer to be fused before the next can be deposited. The purpose of this paper is to present a volumetric AM method in the form of deeply penetrating radio frequency (RF) radiation to improve the speed of the process and the mechanical properties of the polymer parts. Design/methodology/approach The focus of this study was to demonstrate the volumetric fusion of composite mixtures containing polyamide (nylon) 12 and graphite powders using RF radiation as the sole energy source to establish the feasibility of a volumetric AM process for thermoplastic polymers. Impedance spectroscopy was used to measure the dielectric properties of the mixtures as a function of increasing graphite content and identify the percolation limit. The mixtures were then tested in a parallel plate electrode chamber connected to an RF generator to measure the heating effectiveness of different graphite concentrations. During the experiments, the surface temperature of the doped mixtures was monitored. Findings Nylon 12 mixtures containing between 10% and 60% graphite by weight were created, and the loss tangent reached a maximum of 35%. Selective RF heating was shown through the formation of fused composite parts within the powder beds. Originality/value The feasibility of a novel volumetric AM process for thermoplastic polymers was demonstrated in this study, in which RF radiation was used to achieve fusion in graphite-doped nylon powders.