Glow discharge polymer (GDP) material is essential for target ball fabrication in inertial confinement fusion applications. Fine microstructures (∼several tens-hundreds of micros) machining on the GDP surface is required for directing the high-power laser. The machinability and material removal mechanism of the GDP are critical to achieve high surface quality, remaining an unsolved challenge. This study investigated cutting mechanisms of the GDP based on feed per tooth and inclination angle in micro ball-end milling. Chip formation modes and machined surface morphologies as well as their generation mechanism were studied. Three types of chips (i.e., chip clusters, bulk/node chips, banded chips) were formed when the forming force of compression shifts to shear. Thermal effect and plastic flow promote a smooth surface under the squeezing effect of the tool cutting edge. The different ratios of feed rate to tool line velocity caused the micro pits and feed marks on the machined surface with the viscoelasticity of polymer material. By analyzing the cutting force, specific cutting force and machined surface roughness, together with the chip modes and surface morphologies, a transition of cutting modes from ploughing to ploughing-shearing coexistence and then to shearing were revealed. Finally, micro-dimpled structures were machined for validating the influence of the reveled material removal mechanism for fabrication of microstructures. The presented findings are of great significance for the application of micro-cutting processes in future engineering fabrication of microstructures on the GDP target ball.

辉光放电聚合物 (GDP) 材料对于惯性约束聚变应用中的靶球制造至关重要。引导高功率激光需要在 GDP 表面加工精细的微观结构（～几十个微米）。GDP 的可加工性和材料去除机制对于实现高表面质量至关重要，这仍然是一个未解决的挑战。本研究调查了微球头铣削中基于每齿进给量和倾角的 GDP 切削机制。研究了切屑形成模式和加工表面形貌及其产生机理。当压缩的成形力转变为剪切力时，会形成三种类型的芯片（即芯片簇、块状/节点芯片、带状芯片）。在刀具切削刃的挤压作用下，热效应和塑性流动促进表面光滑。由于高分子材料的粘弹性，进给量与刀具线速度的不同比例导致加工表面出现微凹坑和进刀痕。通过分析切削力、比切削力和加工表面粗糙度，以及切屑模式和表面形貌，揭示了切削模式从犁耕到犁剪共存再到剪切的转变。最后，加工微凹坑结构以验证材料去除机制对微结构制造的影响。所提出的研究结果对于微切割工艺在未来 GDP 靶球微结构工程制造中的应用具有重要意义。