Projeto de dispositivo semiautomático para polimento de insertos em politriz metalográfica

Abstract

The technological advancement of machining processes and the increasing demand for dimensional accuracy require high-performance cutting tools with extended service life. However, cutting tools that are not properly prepared reduce process efficiency, leading to increased energy consumption and higher production costs. Individual insert preparation can be performed manually using a metallographic polishing machine. Nevertheless, the manual procedure presents inherent limitations, including low repeatability and a strong dependence on the operator’s experience to control variables such as contact pressure, polishing speed, and contact time, resulting in geometric inconsistencies that accelerate tool wear. This study presents the conceptual design of a semi-automatic device for polishing cutting inserts using a metallographic polishing machine, aiming to address this technological gap. The adopted methodology comprised a review of abrasive finishing processes, cutting tool manufacturing methods, and tool materials, followed by the establishment of design requirements based on the ALP-2 metallographic polishing machine (Alcrisa). The proposed device is based on a mechanism analogous to a slider-crank system. It is driven by a 25 W electric motor equipped with a gear reducer and a variable frequency drive (VFD), enabling precise control of the insert translational speed during polishing. The normal force is applied through a spring-loaded assembly consisting of a screw and compression spring, designed to provide a contact pressure ranging from 10 to 20 N/cm². The supporting structure was designed in aluminum to ensure adequate mechanical strength and corrosion resistance. The design results demonstrate the feasibility of a simple system capable of standardizing the polishing process on a metallographic polishing machine while controlling key process parameters, such as normal force and translational speed, thereby providing greater operational repeatability than manual polishing. As this study is limited to the conceptual design stage, prototype fabrication and experimental validation of the proposed device are recommended for future work.