Master of Engineering Science
Mechanical and Materials Engineering
NRC Automotive & Surface Transportation London, ON
High-aspect-ratio V-grooves constitute microstructures used in surface functionalization applications to control wettability, drag reduction, cell migration, and open capillary microfluidics. However, their precise fabrication represents a crucial challenge in micro-manufacturing due to problems such as riblet deflection, tool wear, and burr formation. This thesis addresses the problem of burr formation by developing an alternating-flank cutting strategy (AFCS) for burr minimization. This study includes a brief overview of different single-point cutting (SPC) strategies, followed by a qualitative finite element analysis of the fabrication challenges. Furthermore, two burr quantitative assessment methods (average burr height and burr volume) were developed for burr characterization. Preliminary analysis suggests that burrs are formed due to plastic deformation and lateral material flow in SPC, which can be minimized through process parameters optimization. Finally, the uniformity of burr formation along the V-groove provides an essential insight into the stability of the process and will require subsequent investigations.
Summary for Lay Audience
Due to the excellent performance of micro-structured functional surfaces, their fabrication has become an attractive field of research because of their prevalent applications in various advanced scientific, technological, industrial, and engineered fields. These applications constitute microstructures used in controlled wettability, friction, light guiding, aero- and hydrodynamics, and several others. Although numerous microstructures are suitable for specific applications, V-grooves are distinct due to their versatility in surface functionalization. Nevertheless, the precise fabrication of high-aspect-ratio V-grooves represents a fundamental technical challenge in advanced manufacturing due to fabrication issues such as dimensional accuracy, tool wear, and micro-burr formation. The formation of burrs becomes a significant issue when dealing with microstructures since its elimination imposes additional time and costs on the fabrication process. To address such an issue, an alternating flank cutting strategy with a constant chip thickness implementation was developed in this thesis. Finite element analysis is used to qualitatively examine the performance of this strategy compared to previously developed strategies in terms of the three fabrication challenges previously mentioned. Moreover, quantitative assessment methods based on the burr height and burr volume were also developed. The preliminary results of this work revealed a strong relationship between the amount of burrs formed and the depth of cut used. The non-uniformity in the burr height assessment was also revealed to help provide insight into the stability of the cutting process, while the burr volume exhibited a more stable quantification of the burrs. Still, both quantitative characterization methods proved efficient in assessing the quality of a single ultraprecise symmetrical V-groove microstructures.
Rangel, Otoniel F., "Alternating-flank Cutting Strategy (AFCS) for Burr Minimization in Ultraprecise Single Point Cutting (USPC)" (2022). Electronic Thesis and Dissertation Repository. 8820.
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