Search Results (9)

Slide burnishing (SB) is a cheap and effective method for improving the surface integrity (SI) and operational behaviour (wear, fatigue, corrosion) of metal components. As its name suggests, SB is implemented through tangential sliding friction and is based on severe plastic deformation of the surface. The review presented here is dedicated to SB implemented using a non-diamond-based deforming element and aims to systematise the achievements from recent decades regarding SB’s effects on the SI, fatigue, wear and corrosion behaviour of metal components. Depending on the burnishing conditions (lubrication, cooling, assisting and their main effects on the treated surface), and based on the difference between the concepts of method and process, a classification of the types of SB processes was made based on the SB method—that is, conventional, sustainable, minimum quantity lubrication-assisted, special, hybrid and combined processes involving SB. Based on this classification, a critical analysis was conducted, viewed through the prism of correlations between the SB, SI and operating behaviour. With sustainability issues becoming increasingly relevant across all industries, more attention is being paid to sustainable SB processes. Because the finite-element method is a powerful and inexpensive tool that can be applied to the analysis of burnishing processes, we used it to build adequate finite-element models of SB processes. At the end of the paper, we outline avenues for future research on SB. Full article

Even though the foundations of diamond burnishing as a research topic were laid long ago, numerous scientific papers still deal with examining various aspects of the burnishing process today. One such aspect is the investigation of the 3D roughness parameters related to the tribological characteristics of the machined surface, which is detailed in the present study. In this study, the positive properties of slide friction diamond burnishing are presented through the examination of surface quality, which plays a key role in tribological assessment. This study analyzed the surface layer condition of X5CrNi18-10 stainless austenitic chromium–nickel steel test pieces after burnishing. Among the finishing operations, burnishing is an economical and low-environmental impact process. The study includes a description of the technological characteristics of turning and diamond burnishing processes. The main characteristics of the Abbott–Firestone curve are described, and parameter improvement factors are introduced. The experimental results and their evaluations are presented by analyzing the values of the Abbott–Firestone surface curves. The study concludes that the best improvement ratios of S_a (arithmetical mean height), S_q (root mean square height), S_z (maximum height) IS_a, IS_q, and IS_z roughness improvements were achieved when using the parameter combination v₂ = 55.578 m/min, f₂ = 0.050 mm/rev and F₄ = 50 N. Full article

Owing to their high producibility and resistance to corrosion, austenitic chromium–nickel steels are widely used in the chemical, petroleum, and food industries. However, their significant disadvantage lies in their poor structural performance, which cannot be improved by heat treatment. This significantly limits the usability of these steels in parts of machines that operate under friction loads. Hardening can be achieved by decreasing the size of grains and applying deformation-induced martensitic transformation. Nanostructuring burnishing (NSB) may be one of the technologies suited for producing parts of tribological assemblies with enhanced operating characteristics. Nanostructuring burnishing using a sliding indenter is being developed as a method of industrial surface nanocrystallization through severe plastic deformation used in the mechanical machining of various types of parts. This article investigates the possibility of enhancing the mechanical and tribological properties of nanocrystallized surfaces of austenitic steels, which are formed through nanostructuring burnishing using a tool with a natural diamond spherical indenter and a change in sliding speed from 40 to 280 m/min with one, three, and five passes. Increasing the tool sliding speed makes surface nanostructuring machining of big parts highly effective. This paper aims to establish the influence exerted by the sliding speed and number of indenter passes on the formation of a nanocrystalline structure, as well as on the modification of microhardness and residual stresses, texture, and tribological properties of the surface layer in the nanostructuring burnishing of AISI 304 steel. Transmission microscopy and microdurometry, 3D-profilometry, and tribological tests of surfaces nanocrystallized with the “ball-on-disk” scheme with dry and lubricated friction established the optimal values of speed and number of passes for a spherical indenter in nanostructuring burnishing. Full article

This article outlines a technology for hole-finishing in short-length cylinder lines to improve wear resistance. The technology is based on an optimized diamond-burnishing (DB) process. The latter was implemented on conventional and CNC lathes, milling machines, and machining centers using a simple burnishing device with an elastic beam. The material used in this study was AISI 321 austenitic stainless steel. The governing factors used were the radius of the diamond insert, burnishing force and feed rate. The objective functions relating to surface integrity characteristics were selected on the basis of their functional importance relative to the wear resistance of the processed hole surface: height and shape roughness parameters, surface microhardness, and surface residual axial and hoop stresses. The one-factor-at-a-time method (used to reduce the factor space), a planned experiment, and regression analyses were used. The multi-objective optimization tasks, which were defined for three diamond insert radius values of 2, 3, and 4 mm, were solved via the Pareto-optimal solutions approach available for a non-dominated sorting genetic algorithm (NSGA-II). Using the optimal values of the governing factors selected from the Pareto fronts, cylinder lines were processed. Samples were then cut from these cylinder lines for reciprocating sliding wear tests under two modes: dry friction and boundary lubrication friction. Additionally, wear test samples were cut from the cylinder line, which was finished with traditional grinding. A finite element simulation was then used to select an appropriate pressing force. The results obtained from the reciprocating sliding wear tests under both the dry and boundary lubrication friction regimes show that to minimize the wear on cylinder lines made of AISI 321 steel, DB with a diamond insert of radius 2 mm is the optimal finishing process. Full article

This study analysed the condition of the surface layer of valve stems made of 317Ti steel after polishing and burnishing. Surface roughness, microhardness, and residual stress tests were carried out. The tests were carried out to determine the effect of the condition of the surface layer (especially non-standard parameters of surface roughness) of the stems on the durability of valves and to determine the possibility of obtaining a favourable state by means of sliding burnishing. Significant differences were observed in the values of the roughness parameters that determine the tribological properties of the surface, and higher surface microhardness and residual compressive stresses were obtained after burnishing. The durability of the stem-graphite seal in a reciprocating movement was tested, and the failure-free operation time of valves with burnished stems was approximately four times longer, which is the premise for recommending sliding diamond burnishing as a finishing treatment for valve stems. Full article

This review paper analyses and summarises the results found while studying the slide burnishing (SB) of metal components refracted through a prism during the surface engineering (SE) process, over the period of January 2019 to January 2023. According to the classification of SE processes defined in the article, SB as a technique in the scope of SE that belongs to the group of static surface cold working (SCW) processes, based on severe surface plastic deformation, and is realised under the condition of sliding friction contact with the treated surface. When the deforming element is natural or artificial diamond, SB is known as diamond burnishing (DB). SB is especially suited for axes, shafts, and holes with circular cross-sections but can also be implemented on flat-face and complex surfaces. SB is eco-friendly and a very economical method for producing mirror-like surface finishes on a wide range of ferrous and non-ferrous machined surfaces, but it can also be realised as a hardening and mixed process with the aim of significantly increasing the fatigue strength and wear resistance of the treated components. Based on a literature review of the results of the theory and practice of SB, an analysis on different criteria was carried out, and graphic visualizations of the statistical results were made. Additionally, the results were analysed using the integrated approach of SE to study the correlations between the apexes of the triangle: SB—surface integrity (SI)—operational behaviour (OB). On this basis, relevant conclusions were drawn, and promising directions for future investigations of SB were outlined. Full article

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. Full article

Additively manufactured metallic parts usually need postprocessing in order to achieve required shape accuracy. Cylindrical test specimens were produced by selective laser melting from Ti6Al4V powder material with different processing parameters. The aim of postprocessing was modification of shape accuracy. Sliding friction diamond burnishing was applied as the postprocessing method. A five-factor, two-level full factorial design of experiment was implemented with factors being infill laser power, infill laser scan speed, burnishing speed, feed and force. Improvement ratios of two roundness parameters were defined, calculated from experimental data, and studied by main effect and interaction analysis. It has been demonstrated that burnishing feed has the largest main effect to improvement in roundness total and cylindricity. Additionally, parameters of both selective laser melting and diamond burnishing appear in three largest interaction terms. Empirical functions were fit to measurement data. Results show that improvement in roundness parameters are strongly nonlinear functions of all factors. Full article

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. Full article