ABSTRACT This work presents the experimental study and optimizing the micro-drilling parameters on geometrical accuracy in micro-drilling on Inconel 800. The geometrical accuracy of the holes is incorporating circularity, overcut, hole damage factor, and taper ratio. In addition to that, material removal rate, machining time, and temperature are taken for study. Micro-holes, based on Taguchi orthogonal array (L27) design, are drilled on the workpiece of 2 mm thickness using uncoated tungsten carbide tools. Medium tool diameter, low spindle speed, and high feed rate resulted in the reduction in the magnitude of machining temperature, machining time, minimum circularity, overcut, hole damage factor, and taper ratio with increased material removal rate. The feed rate, tool diameter, and spindle speed are the order of the influencing parameter on the geometrical accuracy of the hole. The number of holes drilled before tool breakage is 120 in magnitude. Further, the increase in circularity error by 1.12%, overcut, and taper ratio decrease by 60% and 25% from 1st to 120th hole at an optimal level of medium tool diameter, low speed, and high feed rate. From the investigation, 0.8 mm tool diameter can be chosen for micro-drilling of cooling holes in jet engines, printed circuited boards, and biomedical elements.

中文翻译：

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Inconel 800高温合金微孔钻削参数试验研究与优化

摘要 这项工作介绍了在 Inconel 800 上微钻孔的几何精度的实验研究和优化微钻孔参数。孔的几何精度包括圆度、过切、孔损伤系数和锥度比。除此之外，还要研究材料去除率、加工时间和温度。使用无涂层碳化钨刀具在 2 毫米厚的工件上钻出基于田口正交阵列 (L27) 设计的微孔。中等刀具直径、低主轴转速和高进给率导致加工温度、加工时间、最小圆度、过切、孔损伤系数和锥度比的幅度降低，材料去除率增加。进给速度、刀具直径、和主轴转速是影响孔几何精度的参数顺序。刀具破损前钻的孔数量为120个。此外，在中等刀具直径、低速和高进给率的最佳水平下，圆度误差增加 1.12%，过切和锥度比从第 1 孔到第 120 孔分别减少 60% 和 25%。根据调查，可以选择 0.8 毫米的工具直径来微钻喷气发动机、印刷电路板和生物医学元件的冷却孔。