Investigation on chip formation mechanism of high-aspect-ratio micro-milled structures. (August 2022)

• Record Type: Journal Article
• Authors: Han, Jinjin; Ma, Rui; Kong, Linglei; Hao, Xiuqing; Chen, Ni; Li, Liang; He, Ning
• Is Part Of: Journal of manufacturing processes. Volume 80(2022)
• Page Start: 743
• Page End: 753
• Publication Date: 2022-08
• Subjects: Micro-milling -- Chip formation -- High-aspect-ratio micro-structure -- Top-burr -- Side-wall surface; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2022.06.014
• Languages: English
• ISSNs: 1526-6125

Abstract

Abstract: Miniaturized components with High-Aspect-Ratio (HAR) have extensive applications in aerospace, biomedicine, and optical fields. However, the chip formation mechanism of HAR micro-structures is closely related to the machined surface quality and accuracy with insufficient attention at present. The minimum cutting thickness is changing in micro-milling, which leads to the transition from elastic deformation via elastic-plastic deformation to chip formation process. In this work, the chip formation mechanism of micro-structures with High-Aspect-Ratio is thoroughly studied considering the minimum cutting thickness, tool types and milling parameters from the theoretical and experimental perspective. Micro-milling experiments were carried out with single-edged PCD and two-fluted cemented carbide micro-milling cutters, and the chip characteristics and formation mechanism of HAR micro-grooves was further analyzed in detail. The quantitative evaluation of the top-burrs and comprehensive analysis of side-wall surface topography were conducted to investigate the influence of chip formation and chip removal on machined quality of HAR micro-grooves. The results suggest that the chip formation and characteristics of HAR micro-grooves has a significant relationship with the tool performance, milling parameters and side-wall limitation. The aspect-ratio has a negative impact on the effective chip removal which further promotes top-burr dimensions and reduces side-wall surface quality. Sharp micro-cutters with large chip space and exceptional wear-resistance are recommended for machining HAR micro-structures. Graphical abstract: In order to achieve exceptional machined quality of High-Aspect-Ratio micro-structures, this work has investigated the chip formation mechanism in micro-milling. The chip formation and effective chip removal are restricted due to the large aspect-ratio side-wall and cutting-edge size-effect, which further has a negative impact on machined quality. Unlabelled Image Highlights: The chip formation mechanism of High-Aspect-Ratio micro-milled structures is studied in-depth from experimental results. The chip formation and effective chip removal are hindered due to the side-wall limitation and cutting-edge size-effect. Chip material extrusion due to the ineffective chip removal caused by size-effect promotes top-burr dimension. The residual chip material and ineffective chip removal because of size-effect deteriorate side-wall surface quality.