Morphology of Microchips in the Surface Finishing Process Utilizing Abrasive Films

Abstract

In this study, the surface of new lapping films was analyzed, and the lapping finishing process was applied to RG7 tin bronze alloy. The research focused on examining lapping films with electrocorundum grains of nominal sizes 30, 12, and 9 μm, commonly used for achieving smooth surfaces. The manufacturing process involves placing abrasive grains and binder onto a polyester tape, resulting in a heterogeneous distribution of abrasive grains. The study investigates the impact of this random distribution on the performance of lapping films during material removal. Scanning electron microscopy was used to analyze the surface structure of abrasive films, revealing distinctive structures formed by the specific aggregation of abrasive grains. This study explores the influence of different nominal grain sizes on surface finish and aims to optimize lapping processes for diverse applications. The research also delves into microchip analysis, examining the products of the lapping film finishing process. Microchips were observed directly on the abrasive tool surface, revealing insights into their morphology and distribution. The chip segmentation frequency was determined, and they amounted to approximately 0.8 to 3 MHz; these are very high frequencies, which are unique for known chip-forming processes.

Superfinishing with Abrasive Films Featuring Discontinuous Surfaces

“…In the depressions of the tool's irregularities, large quantities of loose abrasive grains were observed (Figure 9), indicating that all these abrasive grains were torn from the binder and were completely uncontrolled in the machining zone, which could have a very negative effect on the formation of individual deep scratches on the machined surface. It is worth mentioning that abrasive grains embedded and bound in the binder penetrate into the workpiece material to a maximum of 10% of their nominal size [18]. However, such loose grains can cause the formation of much deeper scratches [40,41].…”

Evaluation of the Surface Topography of Microfinishing Abrasive Films in Relation to Their Machining Capability of Nimonic 80A Superalloy

“…For research purposes, the coefficient k was adopted at levels of 0.05 Sz, 0.15 Sz, 0.25 Sz, and 0.35 Sz, where Sz was determined individually for each abrasive film. The authors indicated in the study [40] that during the machining with abrasive films, the abrasive grain penetrates into the workpiece material by approximately 10% of the nominal size of the abrasive grain from which the tool is constructed. Based on the fact that abrasive grains are randomly distributed on the abrasive film, and at certain points, several grains may form abrasive aggregates, such a research range was chosen for cognitive purposes.…”

“…An additional oscillatory motion of the tool was applied, with a frequency of 80 Hz. These are the standard machining parameters [40] for the microfinishing process, compiled in Table 1.…”

“…Existing research has explored the impact of abrasive grain size on surface finish to some extent, yet gaps persist in understanding the optimal grain size for microfinishing applications. Moreover, the influence of contact frequency on material removal efficiency and surface integrity requires further elucidation [39,40]. Additionally, the identification and mitigation of wear mechanisms affecting tool longevity are crucial for enhancing process reliability [42,43].…”

Analysis and Basics of Improving the Process of Cutting Electrical Sheet Bundles with a High-Pressure Abrasive Water Jet

“…The challenge lies in determining the critical degree of wear necessary to maintain defect-free cutting edges on electrical steel, preventing the formation of burrs that could potentially create interlayer short-circuit points in the cores of electric machine motors. Efforts are underway to explore methods of cutting electrical sheets and developing tools that mitigate defects in cut edges and preserve the magnetic properties of the sheets [7]. Studies [8,9] investigated the magnetic properties of electrical sheets following laser cutting, EDM, and blanking processes, considering the material's condition after prior processing.…”