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Non-rotational sliding ball burnishing (NRSBB) was developed as a polishing process. The effect of NRSBB parameters on longitudinal and transverse roughness (Ra || & Ra ⊥), and microhardness (MHV) of AA7075-T651 face-milled plate was investigated by response surface methodology. Ra || decreased by increasing the ball diameter. Ra ⊥ increased with increasing the burnishing depth and step over. MHV was enhanced by increasing burnishing depth and passes. The optimal parameters obtained from multi-objective optimization were the ball diameter of 10 mm, burnishing depth of 0.18 mm, step over of 0.062 mm, five passes, and feed rate of 1050.3 mm/min. Compared with the face-milled surface, the optimized NRSBB improved Ra ||, Ra ⊥ and MHV by 93.7%, 89.3% and 37.3%, respectively. The topographic parameters of Sa, Sq, Sp and Sv improved by 89.3 %, 87.5%, 76.4% and 88.9%, respectively. The microhardness distribution of the optimized sample indicated 600 μm hardened depth. [ABSTRACT FROM AUTHOR]

Modern Total Hip Arthroplasty (THA) has evolved allowing orthopaedic surgeons for an exact reconstruction of hip biomechanical parameters thanks to modularity. Modular hip replacement represents, in fact, the best way to reconstruct the joint compared to conventional femoral stems. However, the modular implants are not massively used because of the high risk of breakage. One of the most common causes of their failure is the fretting corrosion at the neck-head interface combined with their relative micro-motion. Thus, the neck component undergoes major wear stresses leading to the implant failure. In order to avoid the risk of failure due to the corrosion fretting, it is necessary to improve the contact surfaces. Furthermore, available actual standards provide long testing procedure for verifying the overall modules fatigue performance thus discouraging researchers to search for possible solutions by changing the manufacturing process of the modules. This work presents a viable manufacturing technique for producing high performance neck components, proposing, at the same time, a faster and reliable testing procedure to predict the wear rate and its driving mechanism affecting the module. Thus, Ti6Al4V neck components have been manufactured by means of burnishing process at varying processing conditions which led to different surface characteristics. Different necks have been tested under real conditions for fretting fatigue simulating a walking loading cycle. Relative micromotions, together with information related to wearing path and operating conditions have been extracted online while testing, using the phase-based motion estimation method (PBME). The overall results demonstrate that burnishing process can tremendously improve the performance under service of the neck component and the proposed testing methodology is able to drastically reduce the testing time improving the reliability of the results. [ABSTRACT FROM AUTHOR]

This study analyses a set of phenomena occurring in the burnished surface layer at the initial moment of deformation formation. The aim of the present research was to explain the phenomena occurring in the top layer of the material during burnishing. The presented analyses include selected laboratory and experimental studies of the process involved in forming burnished surface layers. As shown, conducting an analysis of these processes is purposeful and important because the processes affecting final deformations determine the definitive properties of the burnished surface layers. The final results should help to increase the durability and smoothness of the surface of the products obtained. The feasibility of applying computer technology to determine the three-dimensional shape of the deformation zone formation based on measurements of the stereometry of the contact zone of the burnishing tool with the workpiece material is presented. The process of forming a deformation zone was analysed, revealing that irregularities left over from prior treatment are permanently deformed, and a new structure of irregularities is formed on the machined surface, conditioned by the mechanical, geometric, and kinematic factors of the process. Crucial to this are qualities such as the burnishing load (pressure), the type, shape, and dimensions of the tool, the properties of the workpiece material, and the roughness of the surface before burnishing. The analyses presented here include the first stage of processing, in which initial contact is made with the workpiece, and the period of actual processing, during which plastic deformation of the material occurs in three perpendicular directions, leading to the formation of a material wave on the machined surface just in front of the burnishing tool. [ABSTRACT FROM AUTHOR]

The related work of the diamond burnishing processes focused on improvements in surface quality. The study aims to optimize burnishing factors, including the spraying distance of the nozzle (S), the inlet pressure of the cold air (I), and the quantity of the liquid CO2 (L) of the cool and cryogenic-assisted diamond burnishing operation for minimizing energy consumed (EC) and arithmetical mean surface height roughness (Sa). Burnishing responses are modelled based on the radial basis function network and full factorial data. The entropy method, improved grey wolf optimizer, non-dominated sorting genetic algorithm II, and technique for order of preference by similarity to the ideal solution were implemented to calculate the weights, produce solutions, and select the best outcome. As a result, the optimal data of the S, I, and L were 15.0 mm, 3.0 bar, and 11.0 L/min, respectively. The Sa and EC were reduced by 20.4% and 3.8%, respectively, at the optimality. The optimized outcomes could be employed to improve energy efficiency and machining quality for the internal diamond burnishing process. The optimizing technique could be used to solve complicated issues for different burnishing operations. The cool and cryogenic-assisted diamond burnishing process could be utilized for machining different internal holes. [ABSTRACT FROM AUTHOR]

The publication presents the results of research on the influence of hydrostatic burnishing process on the value of selected parameters of surface roughness, material ratio and surface hardness. The process was carried out on shafts made of the X5CrNi18-10 stainless steel. The prepared samples were subjected to a finishing turning process with constant cutting parameters, and then hydrostatic burnishing was performed on the surface. The tests determined the influence of the variable pressure exerted by the ball on the shaft surface. The evaluation of the research results showed a significant increase in hardness in the surface layer and an improvement in surface roughness parameters and material ratio. The machining process was carried out on a conventional lathe. [ABSTRACT FROM AUTHOR]

Following sustainability in manufacturing, the machining chain can be optimized by either reducing the time and energy consumption of each operation or eliminating the unnecessary operations subjected to keeping the quality of the final product as consistent. However, the roadblock in designing an optimum machining chain is lack of prediction tool to interact between the included operations. In this paper, an integrated algorithm is developed to simulate the surface roughness generation and following modification caused by milling and burnishing, respectively. Predict the surface roughness generation by milling process and its alternation after burnishing. The algorithm works on the basis of clouds of points which were generated in the engagement region of tool and workpiece and their transformation from tool to workpiece coordinate systems. Moreover, some mechanical attributes of the process regarding effect of surface work hardening and elastic rebound were added to the algorithm to enhance the accuracy of simulation. To verify the results, a series of burnishing experiments with multi-roller rotary tool have been carried out on the surface of the finish-milled samples and the surface roughness change was taken into investigation. The obtained results showed that by applying the work hardening and springback effect to predictive algorithm the prediction accuracy of roughness at submicron level enhances up to 50%. It was also found that the most influential parameters influencing the surface roughness after milling-burnishing sequence are milled surface roughness, burnishing force and pass number. In addition, results showed that applying burnishing after rough machining consumes lots of energy to achieve nanoscale surface finish. Accordingly, the sequence of rough-milling, finish-milling and burnishing results in achieving sound surface finish within significantly shorter period of time and applied force. [ABSTRACT FROM AUTHOR]

Ball burnishing has been an effective surface finishing process that generally requires pressing hardened steel rolls/balls, during feed motion, into the surface of the metallic workpiece. The purpose of this study is to examine the improvement of the burnished surface quality by optimizing several burnishing factors, including ball diameter (d), depth of penetration (p), number of passes (N) and type of lubricants (L) for improving surface quality of AISI 1010 steel plates. A second-order mathematical model is developed to predict the surface quality as functions of ball burnishing parameters. The optimal burnishing parameters were determined by conducting central rotatable design matrix experiments and predicting the response models for the surface roughness and hardness. The optimal burnishing conditions for the steel plates were found by using a ball diameter of 12 mm, a burnishing depth of 0.25 mm, a number of passes of 5 and 15W-40 (L3) for the type of lubricant. With these optimal parameters, the mean surface roughness is reduced from Ra = 2.48 to Ra = 0.37 µm, while Brinell hardness increases from 59 to 70.88 HRB. The results show that all lubricants used in this study had negligible effect on the surface hardness. [ABSTRACT FROM AUTHOR]

Aiming to explore the influence of ultrasonic burnishing technology on the wear behaviors of Al7075 alloy friction pairs, the recurrence analysis method is employed to study the evolutions of recurrence plot (RP) and recurrence quantification analysis (RQA) parameters of friction coefficient signals. The results show that the RPs of burnishing Al7075 alloy specimens evolve from an abrupt structure to a homogeneous structure in the wear process. The average value of determinism ( DET ¯) and the average value of entropy ( ENTR ¯) of burnishing specimens as a whole are larger than those of nonburnishing specimens. For the burnishing specimens, the DET ¯ and ENTR ¯ are the highest under the load of 25 N, with the values of 34.2008 and 4.3129, respectively. It demonstrates that the friction system of burnishing Al7075 alloy under the load of 25 N has superior determinism and stability. [ABSTRACT FROM AUTHOR]

Purpose: In this study, two postprocessing techniques, namely, conventional burnishing (CB) and ultrasonic-assisted burnishing (UAB), were applied to improve the fatigue behavior of 316 L stainless steel fabricated through selective laser melting (SLM). The effects of these processes on surface roughness, porosity, microhardness and fatigue performance were experimentally investigated. The purpose of this study is to evaluate the feasibility and effectiveness of ultrasonic-assisted burnishing as a preferred post-processing technique for enhancing the fatigue performance of additively manufactured components. Design/methodology/approach: All samples were subjected to a sandblasting process. Next, the samples were divided into three distinct groups. The first group (as-Built) did not undergo any additional postprocessing, apart from sandblasting. The second group was treated with CB, while the third group was treated with ultrasonic-assisted burnishing. Finally, all samples were evaluated based on their surface roughness, porosity, microhardness and fatigue performance. Findings: The results revealed that the initial mean surface roughness (Ra) of the as-built sample was 11.438 µm. However, after undergoing CB and UAB treatments, the surface roughness decreased to 1.629 and 0.278 µm, respectively. Notably, the UAB process proved more effective in eliminating near-surface pores and improving the microhardness of the samples compared to the CB process. Furthermore, the fatigue life of the as-built sample, initially at 66,000 cycles, experienced a slight improvement after CB treatment, reaching 347,000 cycles. However, the UAB process significantly enhanced the fatigue life of the samples, extending it to 620,000 cycles. Originality/value: After reviewing the literature, it can be concluded that UAB will exceed the capabilities of CB in terms of enhancing the surface roughness and, subsequently, the fatigue performance of additive manufactured (AM) metals. However, the actual impact of the UAB process on the fatigue life of AM products has not yet been thoroughly researched. Therefore, in this study, this paper used the burnishing process to enhance the fatigue life of 316 L stainless steel produced through the SLM process. [ABSTRACT FROM AUTHOR]

Similar to conventional blanking, there are some characteristics, such as rollover, burnish, and fracture on the sides of micro blanked parts, and rollover height and fracture height vary with the blanking clearance. This paper attempts to reveal the effect of blanking clearance on the rollover height. An uncoupled ductile fracture criterion is used to describe the effect of the blanking clearance on the fracture height. The experimental and simulation results show that the increase in hydrostatic stress gradient on the foil around the die edge results in an increase in rollover height. The coefficients of the uncoupled ductile fracture criterion are determined by the method of inverse solution and data fitting. The criterion is evaluated by mean-square error to ensure its validity. This analysis method has been verified by micro brass blanked part. [ABSTRACT FROM AUTHOR]

How do international audiences perceive, and respond to, gender equality reforms in autocracies? For autocrats, the post-Cold War rewards associated with democracy create incentives to make reforms that will be viewed as democratic but not threaten their political survival. We theorize women's rights as one such policy area, contrasting it with more politically costly reforms to increase electoral competition. A conjoint survey experiment with development and democracy promotion professionals demonstrates how autocracies enhance their reputations and prospects for foreign aid using this strategy. While increasing electoral competition significantly improves perceived democracy and support for aid, increasing women's economic rights is also highly effective. Gender quotas exhibit a significant (though smaller) effect on perceived democracy. A follow-up survey of the public and elite interviews replicate and contextualize the findings. Relevant international elites espouse a broad, egalitarian conception of democracy, and autocrats accordingly enjoy considerable leeway in how to burnish their reputations. [ABSTRACT FROM AUTHOR]

Low-plasticity burnishing (LPB) is usually used for finishing of material to enhance service performance by improving the roughness and inducing compressive residual stress to surface and underneath layers. However, processing of nickel-based superalloys by burnishing is usually challenging because of resistance of material against plastic deformation. Therefore, the material should be burnished following multiple pass that results increase of production time. In the present work, a plausible solution, namely electric-current-assisted burnishing (ECAB), is introduced to be used as post-treatment for Inconel 718 material produced by laser powder bed fusion process. The surface integrity aspects, i.e., roughness, hardness, residual stress, microstructure change and fatigue life after LPB and ECAB under different pass number, were compared by as-built material to identify the efficiency of the introduced methodology. The results indicated that for conventionally burnished sample, after second pass, no more improvement in fatigue life of the sample is observed and even it decreases at third pass. On the other hand, it was found that for the ECABed samples, after only a single pass, the fatigue life and surface integrity aspects reach maximum values of conventionally burnished sample implying ECAB causes reduction of production time to one third. Moreover, it was found that in contrast to conventional burnishing process, in ECAB process, due to electroplasticity effect, contribution of pass number in improvement of fatigue life and surface integrity will be more substantial where continuous enhancement is seen up to three pass. Current is applied to the process, the pass number is more influential fatigue life and surface integrity aspects are. [ABSTRACT FROM AUTHOR]

Burnishing is a well-known, low-cost yet effective super finishing method that involves the plastic deformation of the surface layer, resulting in cold working, which improves mechanical characteristics and increases component operating life. Surface quality is primarily related to component service qualities such as wear resistance, corrosion resistance, and fatigue life. This leads to the investigation of ball burnishing as a supportive technique to improve component durability. The purpose of this study is to explore and optimize the ball burnishing process using the Taguchi approach in order to determine the most suitable combination of process parameters to reduce the specific wear rate and coefficient of friction of AISI 1040 steel components. Post-burnishing, hardness improved from 195 to 287 Hv and roughness of surface reduced from 0.447 to 0.101 μm. The optimization findings revealed that 52.35% improvement in wear resistance, whereas coefficient of friction was reduced by 61.53% as compared to the turned surface. The results confirm that ball-burnishing technique enhanced the functional properties of AISI 1040 steel. [ABSTRACT FROM AUTHOR]

Metal products for the metallurgical and machinery industries must meet high requirements in terms of their performance, including reliability, accuracy, durability and fatigue strength. It is also important that materials commonly used to manufacture such products must meet specific requirements. Therefore, various techniques and technologies for modifying the surface layer are becoming more and more widely used. These include burnishing, which may be dynamic or static. This article studies the process of slide burnishing of surfaces of cylindrical objects. The burnishing was performed using a slide burnisher with a rigid diamond-tipped clamp on a general-purpose lathe. The tests were performed for corrosion-resistant steel X2CrNiMo17-12-2. The aim of the research was to determine the impact of changes in burnishing conditions and parameters—feed rate, burnisher depth and burnishing force at a constant burnishing speed—on the surface roughness and hardness. Additionally, the microstructure was assessed in the critical areas: the surface and the core. Another phenomenon observed was surface cracking, which would be destructive due to the occurrence of indentation. In the paper, it was stated that the microstructure, or rather the grains, in the area of the surface layer was oriented in the direction of deformation. It was also observed that in the area of the surface layer, no cracks or other flaws were revealed. Therefore, slide burnishing not only reduces the surface roughness but hardens the surface layer of the burnished material. [ABSTRACT FROM AUTHOR]

This study investigates the surface changes and fretting phenomena at neck-head interface of Ti6Al4V alloy. In particular, hip necks subjected to burnishing process are the objective of the experimental campaign. Ti6Al4V is a widely used material in orthopedic implants due to its excellent biocompatibility and mechanical properties. However, the potential for fretting fatigue is a common concern in hip implants requiring the exploitation of surface modification techniques to enhance the implant's performance and durability. Burnishing process involves the controlled application of mechanical pressure to the implant's surface, which can generate residual stresses and changes in surface topography. By employing advanced surface characterization techniques, including micrograph and profilometry, the surface modifications induced by burnishing were evaluated. Furthermore, fretting fatigue assessment was carried out through mechanical testing, simulating the conditions encountered in the hip joint during typical daily activities. Finally, an emerging sensing technology in the field of non-destructing optical testing, phase-based motion estimation (PBME) was employed in order to assess the surface gradual degradation before failure. [ABSTRACT FROM AUTHOR]

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Extrusion-based 3D printing is widely used in various industries, enabling the rapid creation of prototypes and functional parts at a lower cost compared to traditional technologies. However, one limitation of this technology is the surface finish of the components, where the roughness is not optimal. This paper presents a solution to improve the surface finish of components by leveraging the principles of ironing and ball burnishing. The tool, appropriately heated and passed over the component, smooths out imperfections by uniforming the surface profile. Unlike the traditional ironing method, the use of this tool reduces processing times and enhances surface roughness with a simpler construction and control mechanism compared to a conventional hot-end. The average surface roughness obtained is Ra = 0.796 μm; these values are comparable to those obtained by grinding. The geometry of the tool tips can vary significantly based on specific applications.

Surface damage and corrosion are two major challenges in the long-time functional service life of industrial components. The surface modification approach was previously utilized to improve surface properties and increase corrosion resistance. This paper presents a comprehensive experimental investigation of ultrasonic-assisted burnishing to control surface integrity and corrosion performance of aerospace AA7075-T6 aluminum alloys. To this end, turned sample (control) was treated by conventional burnishing (without ultrasonic vibration), followed by 2D ultrasonic-assisted burnishing. The effect of radial and feed directional vibration on burnishing performance was evaluated. The surface roughness, microstructure, microhardness, and corrosion resistance of the treated samples were assessed. Results indicated that the mean surface roughness of the control sample (turned) was 0.247 µm which decreased to 0.121, 0.081, 0.023, and 0.067 µm after conventional burnishing (CB), ultrasonic-assisted burnishing on radial direction (R-UAB), ultrasonic-assisted burnishing on feed direction (F-UAB), and two-dimensional ultrasonic-assisted burnishing (2D-UAB), respectively. Grain refinement occurred after all burnishing processes and microhardness increased in the depth of 40 µm from 109 HV to 140, 186, 147, and 181 HV after CB, R-UAB, F-UAB, and 2D-UAB treatment, corresponding to 28, 70, 34, and 66% increase, respectively. In addition, the corrosion rate of control sample (turned) was 0.0858 mm/y which was decremented to 0.0541, 0.0498, 0.0249, and 0.0386 after CB, R-UAB, F-UAB, and 2D-UAB treatments, respectively. Interestingly, ultrasonic-assisted burnishing, in particular, along the feed direction outperformed the other treatments by reducing surface roughness and the corrosion rate by about 90 and 71%, respectively. [ABSTRACT FROM AUTHOR]

This work aimed to investigate the effect of the burnishing surface treatment on the tribocorrosion resistance related to Ti6Al4V specimens, in the framework of the head-neck tribo-pair characterising a total hip replacement. The experimental procedure carried out started by choosing the specimens referred to different burnishing conditions together with specimens not treated or treated only with the turning process. Then, tribocorrosion experiments with fixed load and two frequencies were conducted through a reciprocating tribometer equipped with a potentiostat able to measure the electrochemical corrosion potential and current associated to the synergistic wear phenomenon analysed together with the coefficient of friction. Furthermore, optical topographical acquisitions were performed before and after the experiments. The results showed that the non-burnished specimens exhibited unexpected oscillations of the coefficient of friction approximately in the middle of the rubbing phase and the same happens for the cell potential; the wear volume was measured after the tribocorrosion test. This allowed to estimate the wear factor related to all the analysed configurations, showing a greater mean value in correspondence of greater sliding frequencies in the non-burnished cases, while the opposite happens in the burnished cases. Finally, the burnished sample at the lower burnishing force resulted to have the noblest corrosion potential, while the non-burnished samples exhibited the lowest corrosion current density. [ABSTRACT FROM AUTHOR]

The burnishing process's positive changes in the material's properties are measured with different responses. Roughness, stress, and microstructure changes are the main indicators of the internal and external factors faced by the material. Burnishing process as a post-process of critical components to enhance different properties performed by applying pressure on the material to deform plastically for the expected properties enhancement is used in different industries. In this experimental work, C45 steel was face milled by single and multiple-inserts and burnished with a 6mm diameter synthetic diamond ball to study the effect of burnishing force on the surface topography. 3D roughness parameters were used as response parameters measured before and after the burnishing process by AltiSurf 520 of Altimet as they are more representative of topographic changes by different machining processes and procedures than profile roughness parameters. Roughness was reduced significantly after the burnishing process in both cases and a decreasing trend was observed when compared at the same burnishing force. [ABSTRACT FROM AUTHOR]

The new slide roller burnishing (SRB) method has been developed to produce mirror-like surfaces. Unlike conventional roller burnishing (RB), SRB is implemented through a unique device that allows the axes of the deforming roller and the rotary workpiece to cross, resulting in a relative sliding velocity that can be controlled (in magnitude and direction) by varying the crossing angle. In the present work, the effect of SRB on the fatigue behavior of AISI 316 steel fatigue specimens was investigated by comparing it with conventional RB using the following basic correlation in surface engineering: finishing–surface integrity (SI)–operating behavior. To obtain a more representative picture of the comparison, we implemented each method (RB and SRB) with two combinations of governing factors—(A) a radius of the roller toroidal surface of 3 mm, a burnishing force of 250 N, and a feed rate of 0.05 mm/rev (RB-A and SRB-A), and (B) a radius of the roller toroidal surface of 4 mm, a burnishing force of 550 N, and a feed rate of 0.11 mm/rev (RB-B and SRB- B). Both SRB-A (a crossing angle of –45°) and SRB-B (a crossing angle of –30°) achieved mirror-finish surfaces. SRB-B lead to the greatest fatigue strength and, thus, the longest fatigue life among all tested processes. SRB-B created the deepest zone (>0.5 mm) with residual compressive macro-stresses and a clearly defined modified surface layer, whose thickness of more than 20 μm is about twice that created by the other three processes. [ABSTRACT FROM AUTHOR]

This study presents an unconventional flow processing technique that uses glass microspheres instead of abrasives. The fundamentals of flow machining with glass microspheres, including microsphere flow burnishing (MFB) and the conditions necessary for cutting or plastic deformation of a surface to occur during MFB, are determined. Details on such conditions are lacking, and therefore, this study attempts to define these conditions. To this end, MFB was experimentally confirmed to be a burnishing process, and the effects of MFB and abrasive flow machining (AFM) on 2017A aluminum alloy were compared. Both processes achieved a surface roughness (Sa) of < 0.5 μm, while MFB yielded higher values of surface microhardness and compressive stress. The effects of basic process parameters on the MFB and AFM results (workpiece weight loss and Sa) were compared experimentally, and the corresponding mathematical models were established. Utilizing these relationships, MFB parameters can be selected so as to obtain the most favorable surface layer for the expected operating conditions. [ABSTRACT FROM AUTHOR]

Low plasticity burnishing (LPB) is a non-metal removal surface finishing process that enhances the surface integrity and fatigue life of engineering material by using surface sever plastic deformation. However, in some metallic material, the efficiency of process is limited because of excessive work hardening. In this case, plasticity enhancement can be enhanced by applying the electric current following the concept of electro plasticity. However, addition of current density as a new parameter to low plasticity burnishing which itself includes many factors will make the comprehensive optimization of process challenging. To effectively address this issue, in the present work, a study based on the design of experiment was carried out to identify effect of current density as main parameter of electric current-assisted burnishing (ECAB) through its interaction with other LPB parameters like spindle speed, feed rate, current density, pass number, and static force to surface roughness. The experiment was carried out on Inconel 718 fabricated by laser powder bed fusion (LPBF). Correlation between the process factors and surface hardness, roughness, and compressive residual stress as responses was developed using regression analysis followed by analysis of variances. The obtained results showed the current density, followed by pass number and static force have greater contribution on performance measures. Moreover, it was obtained that the pass number plays key role in determining trade-off between process time and products quality characteristics in ECAB. Decision-making based on service performance showed that while applying high density current, a single pass burnishing process (which leads to reduction of process time to one third) can be used for processing of material which is used in high cycle fatigue application, while for low cycle fatigue purpose, the pass number of three secures the service performance. [ABSTRACT FROM AUTHOR]

When placed under cryogenic temperatures (below −180 °C), metallic materials undergo structural changes that can improve their service life. This process, known as cryogenic treatment (CrT), has received extensive research attention over the past five decades. CrT can be applied as either an autonomous process (for steels and non-ferrous alloys, tool materials, and finished products) or as an assisting process for conventional metalworking. Cryogenic impacts and conventional machining or static surface cold working (SCW) can also be performed simultaneously in hybrid processes. The static SCW, known as burnishing, is a widely used environmentally friendly finishing process that achieves high-quality surfaces of metal components. The present review is dedicated to the portion of the hybrid processes in which burnishing under cryogenic conditions is carried out from the viewpoint of surface engineering, namely, finishing–surface integrity (SI)–operational behavior. Analyzes and summaries of the effects of cryogenic-assisted (CrA) burnishing on SI and the operational behavior of the investigated materials are made, and perspectives for future research are proposed. [ABSTRACT FROM AUTHOR]

Duplex steel and cast steels have a wide range of applications in many industrial sectors, for example, oil extraction, printing, petrochemical industry, energy—exhaust gases desulphurization systems, seawater desalination plants, and the shipbuilding industry. The machine elements can be produced with different techniques, which determine the operational properties. A material with the same chemical composition made as a casting will have worse mechanical properties than, for example, a forged element. This depends on the microstructure, its fragmentation and its morphology. However, the costs of casting are lower than, for example, forging, and, in addition, not all shapes obtainable in the casting process can be made using metal–plastic working methods. This article presents research results concerning the influence of the burnishing process on the properties of the duplex cast steel surface layer. The purpose of the research was to verify the impact of static pressure roller burnishing (SPRB) parameters on the wear of the surface layer of duplex cast steel. The subject of the research was cast steel in the GX2CrNiMoN22-5-3 grade—according to PN-EN 10283:2019—that was burnished using 15 variants of technological parameters. Then, the samples were subjected to surface wear tests using the INSTRON 8874 device. On the basis of the observed wear appearances, the acting wear mechanisms are defined and evaluated according their contribution to the wear behavior. Detailed information about the wear phenomena will help industries to minimize their maintenance losses related to surface wear. The possibility of shaping surface properties by mechanical burnishing is part of the current direction of surface engineering development. This technology, combined with a high-potential material such as duplex cast steel, makes it possible to increase wear resistance. [ABSTRACT FROM AUTHOR]

Residual stress and surface finish are prominent members responsible for service attributes of component, like wear resistance, corrosion resistance and fatigue life. This leads to investigate ball burnishing as a supplementary process to enhance durability of component. Burnishing is a well-known, inexpensive yet powerful superfinishing process that includes plastic deformation of surface layer, resulting in cold working which improves mechanical properties and extend components operational life. The aim of the current examination is to investigate and optimize ball burnishing process by Taguchi integrated PCA technique for finding most feasible combination of process variables to decrease specific wear rate and increase corrosion resistance of EN31 steel components. Post-burnishing, hardness improved from 178.5 to 265 Hv and roughness of surface reduced from 0.439 to 0.091 μm. The optimization findings revealed that 52% improvement in wear resistance as compared to the turned surface. X-ray diffraction shows that compressive residual stress was induced exactly under the burnished surface. The observed polarization curves and surface micrographs demonstrate that corrosion resistance is improved and consistent. The results confirm that ball burnishing technique enhanced the functional properties of EN31 steel. [ABSTRACT FROM AUTHOR]

This present study aims to contribute to the literature in understanding the roles of roller burnishing parameters and conditions on Inconel 718 alloy fabricated by Laser Powder Bed Fusion (LPBF). The roller burnishing process was performed with three burnishing forces (300 N, 600 N, 900 N) and under three cooling conditions (namely cryogenic, dry, and preheat). The effects on surface integrity characteristics including surface roughness, microstructure, microhardness, and XRD were investigated. The results illustrate that the burnishing force remarkably influences the decrease the surface roughness under all burnishing conditions. It was possible to reduce the surface roughness from 23 µm to 0.794 µm after turning applied to the as-built part followed by roller burnishing with 900N under dry conditions. When the microstructures were examined, the roller burnishing process caused plastic deformations and reductions in grain sizes. It was observed that the affected layer depth could reach 4.3 µm with 900N under preheat conditions. With the roller burnishing process, it was possible to increase the surface microhardness by 21% depending on the parameter and condition. The roller burnishing process had notable effects on XRD patterns of Inconel 718 alloy fabricated by LPBF. [ABSTRACT FROM AUTHOR]

Surface integrity parameters are the major aspect in the extension of the fatigue life of aero- engine components. In this study, a modified burnishing surface treatment (low plasticity burnishing) with reduced cold work was proposed to improve surface integrity characteristics such as surface finish and hardness, and to induce stable, advantageous compressive residual stress in a cylindrical Ti-6Al-4 V specimen (as-received). In this process, a rolling rigid spherical tungsten carbide ball is pressed across a Ti-6Al-4 V specimen at an appropriate fluid pressure generated by the hydraulic unit. The low plasticity ball burnishing tooling system supported by a hydraulic unit of capacity 30 MPa is designed and developed in this study. By using a suitable specimen holding fixture, the ball burnishing with a small amount of plastic strain was carried out on the Ti-6Al-4 V cylindrical specimen. This research examined the effect of burnishing process variables namely tool pass and burnishing fluid pressure on compressive residual stresses, surface roughness, and hardness in Ti-6Al-4 V. The explicit dynamic analysis was carried out by using FE-Analysis software ABAQUS 6.17 as a part of numerical simulation. Hydraulic burnishing pressure and burnishing passes are the most influential parameters in generating favourable compressive residual stress, qualitative surface finish with less cold work in Ti-6Al-4 V turned specimen. [ABSTRACT FROM AUTHOR]

By directed energy deposition (DED), a flexible design of cooling channels in forming tools, e.g., hot stamping, with a variety of sizes and a high positioning flexibility compared to machining processes is possible. The subsequent ball burnishing of the tool surfaces, in combination with a variation of the DED process parameters, enables control of the tool surface properties and friction behavior. Parameters such as the ball-burnishing pressure or the path overlapping in the DED process are investigated to quantify their effects on roughness, hardness, friction, residual stresses, and heat transfer coefficient of generic tool surfaces. The friction coefficient at elevated temperatures depends strongly on the surface roughness of the tool steel surfaces generated by DED and ball burnishing. The latter process improves the surface integrity: the roughness peaks are leveled by up to 75%, and the hardness and the residual stresses are enhanced by up to 20% and 70%, respectively. However, the roughness of the tool surfaces is determined mainly by the path overlapping of the welded beads in the DED process. Despite the higher surface roughness, the heat transfer coefficient is in the range of conventionally manufactured tool surfaces of up to 2700 W/m2K for contact pressures up to 40 MPa. First hot stamping experiments demonstrate that the tools manufactured by the novel process combination are able to manufacture 22MnB5 hat profiles with an increased and more homogeneous hardness, as well as more homogeneous thickness distribution, compared to conventionally manufactured tools. [ABSTRACT FROM AUTHOR]

Despite the growing demands for personalized items, the capacity of conventional production techniques is restricted to respond to such needs. Instead of conventional manufacturing processes, the intended structure can be directly constructed in a layer-by-layer manner, also known as additive manufacturing (AM). Among AM methods, selective laser melting (SLM) has gained a great deal of attention due to its low cost and availability. However, the poor surface quality in this method is still a problem as it may influence critical mechanical properties of the components like their fatigue life. Therefore, adequate postprocesses are required for additively manufactured metals. In the present study, shot peening (SP) and burnishing were applied as postprocesses to the 316 L stainless steel manufactured by SLM, and then, surface roughness, porosity, microhardness, and fatigue performance were experimentally investigated. Based on the results, the mean surface roughness (Ra) of the as-SLMed sample was 10.907 µm which decreased to 8.543 and 1.324 µm, after SP and the burnishing processes, respectively. Interestingly, the burnishing process was more effective in eliminating near-surface pores and improving microhardness of the samples compared to SP. In addition, the fatigue life of the as-SLMed sample (135,000 cycles) slightly improved after SP (353,000 cycles), while burnishing drastically enhanced the fatigue life of the samples (3,030,000 cycles). [ABSTRACT FROM AUTHOR]

The objective of the research is to analyze the impact of the ultrasonic vibration assistance on the wear resistance due to the topography enhancement caused on Ti6Al4V cylindrical samples after surface modification through a ball burnishing process. The process parameters considered for this study are the burnishing force, the number of passes, and the addition of a 40 kHz ultrasonic assistance, which are thought to enhance the surface topography and increase the hardener effect in terms of depth. A complete screening design of 3 factors was performed, revealing that the number of passes and the vibration assistance are the most important parameters for minimizing the wear volume loss, being 170 N of burnishing force, 3 passes, and the addition of the vibration assistance as the best combination found. However, no significant difference in the friction force was observed. The topography results show that there is a decrease in the average roughness from 1.50 to 0.45 μm with optimal burnishing conditions. It was also analyzed the microstructure originated after the turning, the conventional ball burnishing, and the vibration-assisted ball burnishing, being the last optimal in terms of depth affectation to the microstructure. Therefore, these results confirm an improvement in terms of wear enhancement, friction reduction, and topography results when vibration assistance is added to a conventional ball burnishing process. [ABSTRACT FROM AUTHOR]

The gradient nanostructure is machined on the aluminum (Al) alloy by the two-dimensional ultrasonic surface burnishing process (2D-USBP). The mechanism of why the gradient nanostructure enhances wear resistance is investigated. The mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter, transmission electron microscopy (TEM), and electron backscattered diffraction (EBSD). Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and mechanisms. The effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity (CP) finite element and molecular dynamics (MD) models. The characterization results show that the 2D-USBP sample prepared a gradient structure of ∼600 µm thick on the aluminum surface, increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 GPa. The optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample, with 41.20%, 39.07%, and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5, 10, and 15 N loads, respectively. The gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation; meanwhile, the resistance to deformation, adhesion, and crack initiation and propagation of the sample surface is improved, resulting in enhanced wear resistance. [ABSTRACT FROM AUTHOR]

Degradation caused by corrosion is a major problem for S235JR steel and is responsible for many failures. Ball burnishing is a superficial mechanical finishing treatment that improves surface quality as well as its mechanical properties. The aim of this experimental work is to study the influence of this process on the surface quality and corrosion behavior of S235JR steel. The response surface method (RSM), based on Box-Behnken experimental design, was used to minimize the surface roughness, which has a significant influence on corrosion resistance. "Ra" and "Rz" roughness measurements, as well as 3D surface topography observations, were carried out. Furthermore, the subsurface microhardness distribution was examined, and an X-ray diffraction analysis was performed. The polarization technique (Tafel) and electrochemical impedance spectroscopy (EIS) were used to evaluate corrosion resistance. Finally, analysis by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) was carried out before and after the corrosion tests. The results showed that burnishing force and ball diameter are the main parameters influencing roughness. The optimal regime reduced roughness "Ra" and "Rz" by more than 96% and 97% respectively, producing a smooth and uniform topography. XRD analysis revealed surface grain refinement without phase change. The subsurface microhardness increased to a depth of 40 μm, suggesting a burnished layer of equivalent thickness. Electrochemical corrosion tests and SEM observation showed that the corrosion resistance of the burnished surface was significantly improved, mainly attributed to grain refinement. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technologies revolutionized the manufacturing sector by enabling the production of complex components. But, the poor surface integrity hinders the direct functional application of as-built components and drastically affects the mechanical and tribological performance. In the last decade, researchers employed various post-processing techniques to improve the surface integrity of AM components. Thermal and chemical energy-based post-processes result in thermally destroyed and chemically modified surface layers on the finished surface. In contrast, mechanical energy-based post-processing techniques do not result in any modified finished surface integrities, due to which these techniques were extensively used for post-processing the AM components. The current article focuses on mechanical energy-based severe plastic deformation post-processing techniques to improve the surface integrity of the metal AM components. A detailed review of the published literature specific to each of these processes was carried out, and the research gaps are presented and adequately discussed in this paper. [ABSTRACT FROM AUTHOR]

The study presents the use of spatial imaging of the shape of the deformation formation area occurring at the point of contact between the burnished tool and the processed material surface in the burnishing process. In the analysis of changes in the shape of surfaces processed by ball and disc pressure burnishing, an integrated measurement station was used to measure surface stereometry (New Form Talysurf 2D/3D 120 by Taylor Hobson) and to carry out a series of axially shifted roundness measurements (Talyrond 365 by Taylor Hobson). The geometric parameters of the deformation zone determined in the direction of the circumference of the cylindrical surface (direction of the main movement) and in the axial direction (in the feed plane) are presented. The data obtained as a result of metrological measurements were analysed using specialized computer software. [ABSTRACT FROM AUTHOR]

Chromium–nickel austenitic stainless steels are widely used due to their high corrosion resistance, good weldability and deformability. To some extent, their application is limited by their mechanical characteristics. As a result of their austenitic structure, increasing the static and dynamic strength of the components can be achieved by surface cold work. Due to the tendency of these steels to undergo intercrystalline corrosion, another approach to improving their mechanical characteristics is the use of low-temperature thermo-chemical diffusion processes. This article proposes a new combined process based on sequentially applied diamond burnishing (DB) and low-temperature gas nitriding (LTGN) to optimally improve the fatigue strength of 304 steel. The essence of the proposed approach is to combine the advantages of the two processes (DB and LTGN) to create a zone of residual compressive stresses in the surface and subsurface layers—the enormous surface residual stresses (axial and hoop) introduced by LTGN, with the significant depth of the compressive zone characteristic of static surface cold working processes. DB (both smoothing and single-pass hardening), in combination with LTGN, achieves a fatigue limit of 600 MPa, an improvement of 36.4% compared to untreated specimens. Individually, smoothing DB, single-pass DB and LTGN achieve 540 MPa, 580 MPa and 580 MPa, respectively. It was found that as the degree of plastic deformation of the surface layer introduced by DB increases, the content of the S-phase in the nitrogen-rich layer formed by LTGN decreases, with a resultant increased content of the ε-phase and a new (also hard) phase: stabilized nitrogen-bearing martensite. [ABSTRACT FROM AUTHOR]

The present study focuses on the experimental investigation and optimization of compressive residual stress on ball burnished Mg Ze41A alloy. The optimum compressive residual stress value of −182 MPa is obtained at burnishing force of 50 N, speed of 1200 r/min, feed of 150 mm/min and 4 number of passes. Burnishing force and speed are found to be the most sensitive parameters in affecting the compressive residual stress, followed by number of passes and burnishing feed. The demarcation lines in residual stress-burnishing maps of Mg Ze41A alloy are non-parallel and non-uniform, indicating significant interactions among burnishing parameters. Ball burnishing process imparted desired amount of work hardening, which resulted in homogenized (σx1 = σx2) and isotropic stress (σ 1 = σ 2) state. Additionally, the fuzzy logic model has been deployed to estimate the compressive residual stress values at different burnishing conditions. Fuzzy logic model estimated the results with an error of 6.11%. The results demonstrate that ball burnishing process is an effective method in inducing compressive residual stresses on Mg alloy. The outcome of this study can be of great help in enhancing the fatigue performance of small size products. [ABSTRACT FROM AUTHOR]

Internal burnishing operation is a prominent solution to improve the hole quality. In this study, minimum quantity lubrication (MQL) system parameters, including the diameter of the nozzle (N), impingement angle (I), the pressure of the compressed air (P), the flow rate of the lubricant (L), and the distance between the nozzle and workpiece (D) are optimized for decreasing the total energy consumption (TE), average surface roughness (AR), and air quality indicator (AI) of the internal roller burnishing process. The predictive models of performance measures were developed using the adaptive neuro-based-fuzzy inference system (ANFIS) approach, while a novel model is developed to compute the total burnishing cost (BC). The neighborhood cultivation genetic algorithm (NCGA) and the VIKOR method were used to generate a set of prominent solutions and determine the best selection. The outcomes presented that the optimizing values of the N, I, P, L, and D are 1.0 mm, 35 deg., 0.3 MPa, 70 ml/h, and 10 mm, respectively. The TE, AI, AR, and BC are decreased by 3.1, 9.3, 20.6, and 7.9%, respectively, at the chosen point. The proposed performance measures could be utilized to precisely forecast the responses in the practical burnishing. The developed optimizing method combining the ANFIS, NCGA, and VIKOR could be effectively utilized to deal with complicated optimization issues for machining operations. The observed findings provided efficient information, which could help machine operators to select the optimal MQL system parameters and enhance the burnishing performances. [ABSTRACT FROM AUTHOR]

Permanent prosthesis surface conditions play a key role on the implants overall mechanical performance. Furthermore, the increased number of arthroplasty surgery represents a reason for the necessity of higher quality standards for the biomedical devices. Employing and optimizing severe plastic deformation processes represents a way to obtain implants with higher performance, therefore this work aims, through the application of burnishing process, to combine innovative machining finishing operations coupled with environmentally friendly cooling lubricant techniques to improve the surface integrity and the tribocorrosion resistance of biomedical devices in order to increase their quality, durability and reliability. Another phenomenon taken into account is the tribological behavior that could generates an irreversible transformation of the materials and the release of particles and metal ions in toxic concentrations in the biological environment in which the devices are implanted. One of the most used materials for permanent prosthetic implants is the Ti6Al4V alloy but its tribological behavior is still challenging for the application. In this work Ti6Al4V bars have undergone machining with semi-finishing parameters and burnishing processes, then the effects of sole machining and its combination with burnishing on surface quality and specific wear rate (SWR) have been assessed with respect to as received surface conditions. [ABSTRACT FROM AUTHOR]

This paper presents the effect of burnishing on the surface hardness, selected surface roughness parameters and material ratio of tubes made of an EN AW-6060 aluminum alloy after welding. The prepared specimens were subjected to a 141-TIG welding process, after which the surfaces to be burnished were given a finishing turning treatment with DURACARB's CCGT09T302-DL cutting insert to remove the weld face. After the turning process, the surface finish treatment was carried out by rolling burnishing, for which Yamato's SRMD burnishing tool was used. The surface hardness, selected surface roughness parameters and material ratio were then measured. An analysis of the results showed an increase in hardness in the surface layer, as well as an improvement in the analyzed surface roughness parameters and the material ratio of the native material and the weld. [ABSTRACT FROM AUTHOR]

The amount of wear in cutting tools used in all machining processes is around 1 % to 2 % evaluation of the non-wearing areas of the inserts is economically beneficial. This study aims to test the usability of the non-wearing regions of the waste tungsten carbide (WC), cubic boron nitride (CBN) and ceramic inserts as a rolling tool in the deep rolling method and to observe their performance. The turned workpieces were deep rolled with three different types of waste-cutting tools (WC, CBN and ceramic) in different machining parameters (rolling force, number of passes, and feed rate). As a result, surface roughness and microhardness values obtained in deep rolling operations with these inserts were similar to those in deep rolling operations with other rolling tools. It has been determined that ceramic inserts perform better in deep rolling processes in terms of microhardness, and WC inserts perform better in terms of surface roughness. Thus, it has been determined that waste WC, CBN and ceramic inserts can be used in the deep rolling method. [ABSTRACT FROM AUTHOR]

This paper aims to present a study of the effects of ball burnishing with vibration assistance on the bending fatigue endurance of cylindrical specimens subjected to bending stress and obtain the best input parameters. The specimens were burnished through six different combinations of preload force, number of passes, and vibration assistance, finding that burnishing while applying a 90‐N preload, five passes, and the addition of vibration assistance results in larger fatigue strength. In terms of roughness, it has been proved that vibration‐assisted ball burnishing reduces the mean roughness up to 90%, while enhancing the skewness and kurtosis parameters. The softening effect while deforming, caused by the vibration assistance, helped to reconstruct the surface, obtaining higher depths of affectation and hardening. Fatigue strength was improved by a 6.54% by only adding vibration assistance to the ball‐burnishing process. HighlightsVibration‐assisted ball burnishing enhances fatigue strength by 6.54%.Hardness increase in terms of depth of affectation by means of vibration assistance.The fractography revealed the existance of deeper superficial protective layer (×3) by means of the VA.Surface integrity enhanced by the simple fact of the VA. [ABSTRACT FROM AUTHOR]

The article presents a new method called slide roller burnishing (SRB) for the cold working of cylindrical surfaces on machine tools implemented with a novel multi-functional device. The machined material is chromium–nickel austenitic stainless steel. The deforming element is a toroidal roller whose axis crosses that of the workpiece. As a result, a relative sliding velocity occurs in the contact zone between the roller and the machined surface. The sliding velocity vector is set using the burnishing device. The theoretical background of SRB is presented. When the two axes are parallel, the well-known roller burnishing (RB) method is implemented. Thus, RB is a special case of SRB. Both processes are realized using the multi-functional burnishing device. The RB process was studied experimentally and optimized according to three criteria, based on the relationship between the surface integrity and operating behavior of the respective component, to achieve three processes: smoothing, hardening, and mixed burnishing. Using the optimal RB parameters obtained, the dependence of the results of SRB on the crossing angle was investigated and optimized. A comparative analysis was performed between the optimized RB and SRB processes (respectively for their three variants: smoothing, hardening, and mixed) based on geometrical and physical–mechanical characteristics of the surface integrity. The main advantage of the SRB is that it provides smaller height roughness parameters (improvement by 42%) and a higher surface microhardness (improvement by 7%) than RB. [ABSTRACT FROM AUTHOR]

In deep rolling, ball and roller type burnishing tools are generally used. It is generally difficult to deep roll contours with curved and conical shapes with the existing rolling tools. The aim of this study is to design experiments with a roller insert that will be an alternative to deep rolling inserts being used now and that can be fixed on the present tool holders; and to investigate the usability of them including curve and conical formed workpieces with the help of this designed tool. For this purpose, a spherical insert with a radius of 1 mm in the form of WNMG was designed based on the WNMG insert model and used in deep rolling of Al6061-T6 material using different forms and parameters. 143, 330, 495 N rolling force, 0.04, 0.08, 0.12 mm/rev feed and 400, 600, 800 rpm spindle speed were selected as rolling parameters. By examining the microhardness and surface structure of deep-rolled Al6061 parts, the achievability of the results of existing tools in deep rolling was investigated. At the end of the study, it was determined that the new type of rolling tool produced results similar to the existing tools in deep rolling in terms of microhardness and surface morphology, which enabled that the workpieces with curve and conical forms could also be rolled, and that this rolling tool could be used as an alternative in deep rolling. [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental research and surface characteristics after the process of roller burnishing of macro-asperities of the surface. As part of the work, the possibility of plastic shaping of the surface macrostructure with indentations (plateau structure), which will show anti-wear properties through appropriate surface shaping and the compressive stress state in the product's top layer, was investigated. The essence of the paper is to present the analysis of the surface roughness parameters and carry out analysis of SEM, AFM and metallographic results for the burnished surface. The main objective of the work is to develop an adequate outline of the surface to receive the required parameters and characteristics of the surface after burnishing. The results of dependencies of roughness parameter after turning and after burnishing from the vertical angle of asperities are presented, as well as SEM, AFM and metallographic analysis for the surface with a vertical angle of 60 ÷ 150 degrees. [ABSTRACT FROM AUTHOR]