Search Results (7)

The study introduces new technologies of microfinishing, which are primarily aimed at cylindrical surfaces but with machining effectiveness, precision, and surface longevity. In the newly proposed dual-zone microfinishing method, symmetrical abrasive film feeding systems are adapted with a lever mechanism and a pivoting pressing assembly to simultaneously conduct processing in two zones. With such a design, uniform force distribution is ensured, while mechanical deformation is reduced to raise the utility of the abrasive film and lower scraps for better economic performance. Also, the application of microfinishing operations combined with carbon layer deposition using graphite-impregnated abrasive films is introduced as a novel method. This process combines surface refinement and the forming of wear-resistant carbon coatings into one single operation, resulting in increased wear resistance and reduced forces of friction. Further stabilization of the conditions for microfinishing is achieved by immersing the processing zone in a fluid medium due to increased lubrication, improvement in heat dissipation, and the optimization of surface properties. It is particularly suitable for high-precision applications and a maintenance-free environment such as military, vacuum, and low-temperature systems. The experimental results show the effectiveness of the proposed methodologies, underscoring their ability to create remarkably smooth surfaces and very robust carbon textures simultaneously. Full article

This research explored the formation and effects of carbon layers on Grade 5 titanium alloy (Ti–6Al–4V) surfaces during a microfinishing process using both traditional abrasive films and graphite-coated abrasive films. The study tried to appraise the effect of using graphite-coated films in the microfinishing process concerning surface roughness. Microfinishing with an abrasive film impregnated with diamond particles and an additional coating of graphite was performed to minimize surface roughness and enhance the overall performance of the surface. As a result, it was shown that after processing, the uniform carbon texture formed by the graphite-coated film significantly improved the lubricating and thermal properties. Energy dispersive spectroscopy (EDS) analysis confirmed the homogeneity of carbon distribution over the whole treated surface. Moreover, the graphite-coated films enabled us to obtain smoother surfaces with improved tribological properties. The study therefore concluded that the inclusion of graphite in the abrasive films is necessary for effecting surface modification in light of considerable improvements in surface quality and performance, especially where the wear needs to be reduced and the integrity of the surface maximized. Full article

This work investigates the contact between abrasive particles and workpieces in microfinishing processes with special consideration given to the determination of unit force, unit pressure, and grain, the forces exerted by individual abrasive grains. A detailed methodology was established for measuring the contact area, penetration depth, and circumferences of grain imprints at depths corresponding to multiples of the total height of the abrasive film, represented by the parameter Sz. The following depths were analyzed: 0.05 Sz, 0.15 Sz, 0.25 Sz, and 0.35 Sz. Results show that the areas closer to the central microfinishing zone bear the highest unit pressures and forces and, thus, contribute dominantly to material removal. It was further found that near the edges of the contact zone, the pressure and force have been reduced to lower material removal efficiency. The non-uniform geometry of abrasive particles was found to significantly affect contact mechanics, more at shallow depths of penetration, whereas the shape of the apex defines the nature of the interaction. A parabolic force and pressure distribution were evident for the irregular load distribution of the microfinishing area. The result brings out the need for further refinement in the design of the abrasive film and pressure distribution in order to achieve improvement in uniformity and efficiency during microfinishing. It would bring out valuable insights on how to improve the effectiveness of an abrasive film and ways of optimizing the process conditions. The results provide a founding stone for further advancement of knowledge in the grain–workpiece interaction, enabling better surface quality and more reliable microfinishing processes. Full article

Ti–6Al–4V is the most commonly used alpha–beta titanium alloy, making it the most prevalent among all titanium alloys. The processed material is widely employed in aerospace, medical, and other industries requiring moderate strength, a good strength-to-weight ratio, and favorable corrosion resistance. A microfinishing process on the titanium alloy surface was conducted using abrasive films with grain sizes of 30, 12, and 9 μm. Superfinishing with abrasive films is a sequential process, where finishing operations are performed with tools of progressively smaller grains. The surface topography measurements of the workpiece were taken after each operation. The experiment was in the direction of developing a new surface smoothness coefficient considering the number and distribution of contact points so as to properly evaluate the quality of the surface finishing. The results showed that the finest-grain films gave the most uniform contact points, thus offering the best tribological characteristics; the 9 LF (micron lapping film) tools gave the smoothest surfaces (Sz = 2 µm), while the biggest-grain films, such as the 30 FF (micron microfinishing film), were less effective since large protrusions formed. This is a suitable study to explore the optimization paths for the superfinishing of titanium alloys, with implications for improving the performance and longevity of components in critical industrial applications. Full article

This study presents research into the unique method of depositing carbon layers onto processed surfaces, during finishing with abrasive films, on a global basis. The authors of this article are holders of the patent for this method. What makes this technology outstanding is that it integrates processes, whereby micro-finishing and the deposition of a carbon layer onto freshly exposed surface fragments is achieved simultaneously, in a single process. Among the main advantages accruable from this process is the reduction of surface irregularities, while the deposition of a carbon layer is achieved simultaneously. Ultrathin graphite layers can be widely used in conditions where other methods of reducing the coefficient of friction are not possible, such as in regard to micromechanisms. This article illustrates the application of carbon coating, end on, on a surface processed with abrasive film, containing intergranular spaces, saturated with graphite. Thin carbon layers were obtained on two substrates that did not contain carbon in their initial composition: soda–lime glass and a tin–bronze alloy. It was performed through microscopic examinations of the produced surface, roughness analyses of these surfaces, and analysis of the chemical compositions determined by two methods, namely EDS and GDOES, proving the existence of the coatings. The aim of this paper is to prove the possibility and efficiency of using graphite-impregnated lapping films in the deposition process of carbon films, with improved surface smoothness, durability, and wear resistance. The produced coatings will be tested in regard to their operational properties in further research. The authors underline the potential of this method to revolutionize surface treatment processes, due to the significant advantages it offers across various industries. Full article

This study investigates the surface topography of microfinishing abrasive films and their machining capability on the Nimonic 80A superalloy, a high-performance nickel-based alloy commonly used in aerospace and gas turbine engine applications. Surface analysis was conducted on three abrasive films with nominal grain sizes of 30, 15, and 9 μm, exploring wear patterns, contact frequency, and distribution. To assess the distribution of grain apexes, Voronoi cells were employed. Results revealed distinct wear mechanisms, including torn abrasive grains and cracked bond surfaces, highlighting the importance of efficient chip removal mechanisms in microfinishing processes. Larger grain sizes exhibited fewer contacts with the workpiece but provided more storage space for machining products, while smaller grain sizes facilitated smoother surface finishes. The research demonstrated the effectiveness of microfinishing abrasive films in reducing surface irregularities. Additionally, surface analysis of worn abrasive tools provided insights into wear mechanisms and chip formation, with the segmentation of microchips contributing to efficient chip removal. These findings underscore the significance of selecting appropriate abrasive films and implementing effective chip removal mechanisms to optimize microfinishing processes and improve surface finishing quality in advanced material machining applications. It is worth emphasizing that no prior research has investigated the microfinishing of components crafted from Nimonic 80A utilizing abrasive films, rendering this study truly unique in its contribution to the field. Full article

This article presents a comprehensive investigation into pressure rollers utilized in the microfinishing process, covering aspects such as design, experimental properties, compliance, and finite element simulation. Prototype pressure rollers with unconventional elastomer configurations were designed and analyzed to explore their effectiveness in achieving superior surface finishes. Experimental analysis and finite element simulations were conducted to gain insights into the performance and behavior of these pressure rollers under various loading conditions. This study addresses the validation of constitutive material models used in finite element simulations to ensure accuracy and reliability. The results indicate that the applied material model, validated through experimental analysis, accurately predicts pressure roller behavior. Finite element simulations reveal distinct contact zone patterns and stress distributions across the contact surfaces, highlighting the importance of considering deflection-induced variations in contact behavior. Additionally, the investigation evaluates the effectiveness of different pressure rollers in removing surface irregularities during the microfinishing process. Roller R3 demonstrates the highest efficacy in removing surface peaks, suggesting its potential for achieving superior surface finishes. Overall, this research contributes to the advancement of microfinishing techniques by providing insights into pressure roller design, performance, and behavior, thereby optimizing microfinishing processes to produce high-quality components. The urgency of this study arises from the growing need for exceptional surface finishes in various industrial sectors. With manufacturing industries increasingly pursuing high-precision components boasting flawless surface quality, the significance of microfinishing processes is highlighted. Full article