Surface roughness is an important factor in metal cutting, and usually different surface roughness characteristics are used to control the quality of the machined surfaces. However, as the cutting tool wears out during the cutting process, the roughness values change. In most cases, theoretical roughness values are calculated without taking the wear characteristics of the tool into account. For this reason, the calculated and measured roughness values may differ from each other, and the tendency of their change may also be different. This paper presents a method for the determination of the theoretical roughness of hard turned surfaces considering the wear of the cutting tool. The purpose of the analyses performed was to show the effect of wear trace on the tool and the roughness of the machined surface and to give a possible method to take the wear into account when calculating the theoretical roughness values. During the investigations, the shape of the actual (worn) edge section of the cutting tool was recorded by an optical microscope, and the theoretical surface roughness values were calculated with that profile by a CAD modeling method developed earlier. Cutting experiments were conducted on a lathe machine with two similar cutting tools, one of them has significant tool wear, while the other was a completely new one. The calculated theoretical roughness values were compared with real measured roughness values, and the error of the estimates was between 8.7 and 68.3%, larger errors were found at lower feeds.

Selective laser melting is a frequently used, powder bed fusion additive manufacturing technology for producing metallic parts. However, appropriate surface quality cannot be achieved, so post-processing is often necessary. Subsequent machining of surfaces serves multiple objectives such as improvement of dimensional accuracy, changing surface roughness and modification of the residual stress state for higher surface hardness. Beyond its several advantageous properties, Ti6Al4V material has, as its weaknesses, low tribological behavior and wear resistance. Sliding friction burnishing is a conventional chipless and coolant-free environmentally conscious technology for surface modification that is appropriate for simultaneously decreasing surface roughness and increasing surface hardness. Until now, there has been a research gap regarding the diamond burnishing of selective laser melted Ti6Al4V parts. In this study, we investigated how the surface roughness of selective laser melted parts can be modified via sliding friction burnishing. 2D and 3D characteristics of surface roughness were measured by a chromatic roughness measuring device. Indices of surface roughness improvement were defined and studied as a function of selective laser melting parameters. Optimal manufacturing parameters of laser power—P = 280 W and scanning speed u = 1200 mm/s—for effective surface improvement via burnishing are proposed.

This study describes the determination and optimization of burnishing process parameters and their effects on surface roughness of EN AW-2011 aluminium alloy workpieces. The process has a low environmental load and the chip-free burnishing process improves the integrity of the machined surface, but to achieve this, the different burnishing parameters, for example, burnishing force, feed rate, speed and number of passes, must be properly defined according to the material of the workpiece. In our research, a full factorial experimental design method is used to plan and carry out the experiments and to determine the most appropriate parameter range for this material quality.

Sliding friction diamond burnishing is a finishing machining operation whose purpose is to improve the surface integrity of previously machined surfaces and increase their surface hardness. When analyzing a complex process involving plastic deformation, friction, and the interaction between solids, finite element models (FEMs) involve a significant amount of simplification. The aim of this study is to investigate a 2D FEM of the residual stress occurring during diamond burnishing. Before burnishing, the samples were processed by fine turning. Based on the simulations and laboratory experiments performed, it can be concluded that the diamond burnishing process can be modeled with relatively good approximation using two-dimensional modeling. It was also concluded that it is important to consider the initial surface topography in two-dimensional tests. The results indicate that the diamond burnishing process improved the residual stress properties of EN 1.4301 austenitic stainless steel by creating relatively high compressive stress, whose magnitude was between 629 and 1138 MPa depending on the applied force. However, the stress distribution is not uniform; it is mostly concentrated under the roughness peaks.

The current research aimed to investigate the critical buckling load of a simply supported aerospace-grade stiffened panel made of additively manufactured cubic lattice unit cell arrays, namely simple cubic, face-centered cubic (FCC) and body-centered cubic (BCC) structures. Ansys Design Modeler was chosen to design and analyze the critical buckling load of the panel, while a popular material, Ti-6Al-4V, was used as the build material. Numerical validation on both the stiffened panel and a lattice beam structure was established from multiple resources from the literature. Finally, the panels were tested against increments of a strut diameter ranging from 0.5 mm to 2 mm, which corresponds to a relative density of 6% to 78%. It was found that considering the relative density and fixed relative density, the simple cubic lattice cell outperformed the buckling results of the FCC and BCC panels. Moreover, the relationship of the parameters was found to be non-linear. Finally, the data samples collected from numerical outcomes were utilized to train four different machine learning models, namely multi-variable linear regression, polynomial regression, the random forest regressor and the K-nearest neighbor regressor. The evaluation metrics suggest that polynomial regression provides the highest accuracy among all the tested models, with the lowest mean squared error (MSE) value of 0.0001 and a perfect ${\mathrm{R}}^2$ score. The current research opens up the discussion of using cubic lattice cells as potential structures for future stiffened panels.

Diamond burnishing is a finishing precision machining that is often used to improve the quality characteristics of previously machined surfaces. With its help, the surface roughness can be reduced, the surface hardness can be increased, and the tensile stresses remaining in the surface after cutting can be transformed into compressive ones, and these changes can increase the service life of the components. Diamond burnishing was typically developed for processing cylindrical surfaces and is most often used for this type of surface. In this manuscript, we present a new method with the help of sliding burnishing, which can also be used on flat surfaces. By using the clamping head of a special tool into the main spindle of the vertical milling machine and moving it along a suitable path, the flat surface can be burnished. Machining experiments were carried out with the new type of tool on general-purpose, unalloyed, structural carbon steel samples on which the flat surfaces were previously generated by face milling. The examined parameters were the burnishing force F, the feed f_b, and the number of passes (NoP). The L9 Taguchi experiment design was applied for executing flat slide burnishing, and the examination was conducted by ANOVA analysis. This research contributes to the field by providing insights into optimizing the burnishing process parameters for achieving desired surface quality in milling operations.