Han Jinjin, Ma Rui, Hao Xiuqing, Kong Linglei, Chen Ni, Li Liang, He Ning
College of Mechanical Engineering, Jiangsu University of Technology, Changzhou 213001, China.
College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China.
Micromachines (Basel). 2021 Sep 29;12(10):1170. doi: 10.3390/mi12101170.
Deep-and-narrow micro-grooves are the common functional structures of miniature parts. The fabrication of the micromilled grooves with high quality and accuracy is the essential guarantee of the causative performance for these miniature parts, and micromilling is the most versatile process to machine such micro-grooves. However, micromilling technology is a highly tool-dependent process, and the commercial carbide micromilling cutter has shown obvious deficiencies in terms of rapid tool wear and inferior machined quality during the machining process. In this paper, a polycrystalline diamond (PCD) micromilling cutter with a large-aspect-ratio (LAR) was designed and prepared by the self-proposed hybrid fabrication method of laser and precision grinding. Micromilling experiments on oxygen-free copper were conducted, and the carbide micromilling cutter was selected in the comparative experiments. The variations of milling forces and specific energy were analyzed through the parameter experiments. Then, the surface quality, machined accuracy and tool wear were further investigated. Results showed that the PCD micromilling cutter with an aspect ratio of 3.25 was successfully manufactured by the proposed hybrid method. The self-fabricated PCD micromilling cutter presented remarkable superiority in terms of the surface quality, machined accuracy, and tool wear when preparing deep-and-narrow micro-grooves. Finally, a satisfactory micromilled groove with an aspect ratio of 2.5 was achieved with the self-fabricated LAR PCD cutter under the optimized conditions.
深而窄的微槽是微型零件的常见功能结构。高质量、高精度地加工微铣槽是这些微型零件获得预期性能的基本保证，而微铣削是加工此类微槽最通用的工艺。然而，微铣削技术是一个高度依赖刀具的工艺，商用硬质合金微铣刀在加工过程中表现出刀具磨损快和加工质量差等明显缺陷。本文采用自行提出的激光与精密磨削混合制造方法，设计并制备了一种大长径比（LAR）的聚晶金刚石（PCD）微铣刀。对无氧铜进行了微铣削实验，并在对比实验中选用了硬质合金微铣刀。通过参数实验分析了铣削力和比能的变化。然后，进一步研究了表面质量、加工精度和刀具磨损情况。结果表明，采用所提出的混合方法成功制造出了长径比为3.25的PCD微铣刀。在加工深而窄的微槽时，自制的PCD微铣刀在表面质量、加工精度和刀具磨损方面表现出显著优势。最后，在优化条件下，用自制的大长径比PCD刀具加工出了长径比为2.5的令人满意的微铣槽。
