Improving the surface roughness quality of 3D printed components, especially metallic ones, which are fabricated from the selective laser melting (SLM) method, has drawn enormous attention from the research community. It should be noted that various studies on this topic have reported that precise surface roughness results can be obtained with various techniques that are indeed not cost-effective. Differing itself from these studies, this manuscript investigates an economical solution for fabricating and surface treating SLM components. Specifically, the inspected specimens were printed with recycled 316L stainless steel powder and treated solely with two abrasive surface finishing methods. In the manuscript, two scanning strategies namely meander and stripes, and three types of surfaces were investigated. Subsequently, their 2D and 3D surface roughness results were elaborated. After the proposed herein abrasive treatment, 3D surface roughness arithmetical mean height of a surface (Sa) value of 0.9 µm can be achieved.

In this paper, a practical issue of the application of cubic boron nitride (CBN) cutting tools for the machining of steel 100Cr6 thin-walled bearing rings is addressed. Three geometries of the commercially available CBN cutting inserts were tested at different machining parameters. The effect of geometry was assessed in terms of surface integrity, considering 2D profile parameters, 3D topography of the surface, and residual stresses in the surface layer. The results were sometimes contradictory, since the same cutting inserts provided the largest and the lowest values of the topography parameters, dependent on different cutting conditions. In general, CBN cutting inserts with XCEL geometry ensured the smallest profile parameters Ra and Rz, and the spatial parameters of Smr1 exhibited the largest values among all tested tools, suggesting reduced wear resistance. Residual stresses analysis did not reveal any inacceptable or potentially dangerous surface layer state after machining.

Lattice and gyroid structures are often subjected to additive technologies to produce various types of products, and the current market has a number of 3D printers that can be used for their production. The quality of the products produced in this way can be assessed on the basis of technical parameters and the filament used. Such an approach, however, is insufficient. In terms of quality, other product parameters need to be assessed, such as the surface texture and the internal structure’s porosity. For such an assessment, we can use the industrial tomography method and the method of roughness measurement via an optical microscope. The paper presents research on the assessment of the surface texture and porosity in lattice and gyroid structures. For the research, two types of test specimens—a specimen with a lattice structure and a specimen with a gyroid structure—were prepared. The obtained results proved that the 3D printing technology directly impacted the surface texture and porosity. For experimental specimens produced by SLS technology, we found that it was very important to carefully remove the excess powder, as unremoved powder can significantly affect the porosity results. For specimens produced by FDM technology, the research confirmed that some “gaps” between the layers were not pores but defects created during specimen production. When analyzing the surface using the Alicon Infinite G5 optical microscope, we found that the measured roughness results were directly impacted by the specimen’s surface color, the structure’s geometry, and the ambient light, which was confirmed by a red lattice experimental specimen, the surface of which could not be scanned. Based on the above, it can be stated that the selection of 3D technology for additive production needs must be given adequate attention regarding the quality of the created structures and textures.

Domination plays an indispensable role in graph theory. Various types of domination explore various types of applications. Equal-status people work together and interlace with each other easily. In this paper, the paired equitable domination of a graph, its inflated graph, and its complement of an inflated graph were studied. The relationship between the domination number of the graph, the equitable domination number, and the paired equitable domination number of complements of the inflated graph were established. Furthermore, we proved the Nordhaus–Gaddum-type inequality, that is, ${\gamma }_{pr}^e(H)+{\gamma }_{pr}^e(H)\le 6$ if $H$ is a graph with m nodes where $m\equiv 0, 2(mod 8)$ and $d(a_i)$ = (m/2) for all $a_i$. The challenges and limitations of this parameter of paired equitable and equitable domination depends on the degree of the vertex of the graph. Practical applications are discussed in various fields and illustrated using the studied parameter.