Ball Burnishing Process Research Articles

Enhancing Surface Topology of Udimet®720 Superalloy through Ultrasonic Vibration-Assisted Ball Burnishing

This contribution reports the effects of an ultrasonic-vibration assisted ball burnishing process on the topological descriptors of nickel-based alloy Udimet®720. This material is of high interest for the transportation industry, and specifically for the aeronautical sector. Despite the acknowledged necessity to finish this material to achieve excelling mechanical performances of parts, surface integrity enhancement by means of plastic deformation through ball burnishing has seldom been explored in previous references so far. In this paper, different surface descriptors are used to report how the topology changes after ultrasonic-assisted ball burnishing, and how burnishing conditions influence that change. The burnishing preload and the number of passes are the only influential factors on surface change, whereas the feed velocity of the tool and the strategy reveal not to be relevant on the result. Additionally, the extent to which the process successfully modifies the objective surfaces is highly divergent depending on the original scale of the treated surface. The assistance of the process with vibrations also shows that the resulting topologies are characterized by a periodical pattern of repetitive peaks and valleys that are extended on the surface with a higher frequency in comparison to the non-assisted process, which could influence in the functional deployment of workpieces treated through it, and could deliver an advantage with regard to its non-assisted homologous process.

Influence of Ball Burnishing Process on Equal Channel Angular Pressed Mg-Zn-Si Alloy on the Evolution of Microstructure and Corrosion Properties

In the present study, Mg-4Zn-1Si alloy was subjected to equal channel angular pressing (ECAP) up to 4 passes at 300 °C, followed by ball burnishing using 0.3 mm depth of press, 300 mm/min feed and 1 pass successfully. The effect of ECAP and ECAP + ball burnishing process on microstructure, mechanical properties (tensile and hardness) and corrosion behavior was systematically investigated. After 4 pass ECAP, initial coarse grains (210 μm) were refined and average grain size is 6 μm and after ball burnishing, the grain size is found to be 3.3 μm. Microstructure evolution is discussed using optical images, scanning electron microscope images and transmission electron microscope images. For ECAP samples, maximum strength and hardness was recorded at 3 pass. Both strength and hardness decreased for 4 pass ECAP processed samples, even though grain size decreased, this is because of texture modification in the material. ECAP 4 pass + ball burnished samples exhibited 48.5% enhancement of microhardness as compared to 4 pass ECAP samples. Corrosion resistance of the samples decreased with increase in the number of ECAP passes, this is due to strain-induced grain refinement with more crystalline defects in samples. Combined process of ECAP and ball burnishing effectively reduces the Icorr and this consequently reduces corrosion rate of the Mg–4Zn-1Si alloy.

Improving the surface integrity of the CoCrMo alloy by the ball burnishing technique

The CoCrMo alloy is a biomaterial that has been employed for the production of permanent orthopedic implants, however, the release of metallic ions from debris due to tribocorrosion is the main drawback for its extended application. In this paper, we propose the use of the ball burnishing process to improve the surface properties of the CoCrMo alloy. A 32 factorial design of experiments (DoE) was conducted to achieve a basic understanding of the relationship between the surface hardness, roughness and corrosion current (response variables) and the force and number of passes of the burnishing tool (input factors). Statistical analysis showed that force is the most significant factor for changing the surface properties. At the best experimental conditions, hardness was improved by 41.4%, the roughness was decreased by 72.7% and the corrosion rate was noticeably reduced by 92.4%. Microscopy and X-ray diffraction analysis showed that ball burnishing introduces changes in the microstructure, generating a surface layer with improved properties. It is concluded that the ball burnishing process is suitable for improving the surface properties of the CoCrMo alloy under an appropriate combination of experimental conditions.

Finite Element Analysis of Ball Burnishing on Ball-End Milled Surfaces Considering Their Original Topology and Residual Stress

Ball burnishing is a superfinishing operation whose objective is the enhancement of surface integrity of previously machined surfaces, hence its appropriateness to complement chip removal processes at the end of a production line. As a complex process involving plastic deformation, friction and three-dimensional interaction between solids, numerical solutions and finite element models have typically included a considerable amount of simplifications that represent the process partially. The aim of this paper is to develop a 3D numerical finite element model of the ball burnishing process including in the target workpiece real surface integrity descriptors resulting from a ball-end milled AISI 1038 surface. Specifically, its periodical topological features are used to generate the surface geometry and the residual stress tensor measured on a real workpiece is embedded in the target surface. Secondly, different models varying the effect of the coefficient of friction and the direction of application of burnishing passes with regards to the original milling direction are calculated. Results show that the resulting topology and residual stresses are independent of the burnishing direction. However, it is evident that the model outputs are highly influenced by the value of the coefficient of friction. A value of 0.15 should be implemented in order to obtain representative results through finite element models.

Monitoring of Processing Conditions of an Ultrasonic Vibration-Assisted Ball-Burnishing Process.

Although numerous references present the beneficial effects on surface integrity of ultrasonic vibration-assisted ball burnishing (UVABB), nothing has been reported about the dynamic behavior of the UVABB tool, workpiece, and machine triad during the process. In this paper, a dynamic monitorization through a set of 5 accelerometers is tested to analyze the interactions between the tool–workpiece–machine mechanical assembly. A UVABB tool attached to a milling machine and equipped with a piezoelectric stack that is able to assist the process with a 40-kHz vibration is tested on a milled C45 steel surface. First, the natural frequencies of the mechanical system are obtained through hammer impact tests. Then, the vibratory signals transmitted during the execution of the process are monitored and compared to those: two feed velocities and two burnishing preloads, all with and without vibration-assistance. Results show that the proposed accelerometer set is valid to assess the behavior of a UVABB process. The system’s natural frequencies are not varied by vibration-assistance and are not excited when the piezoelectric is functioning. It is confirmed that UVABB is safe for the machine and the tool, and there is no unexpected excited frequencies due to the piezoelectric excitation.

Ball-burnishing factors affecting residual stress of AISI 8620 steel

Ball burnishing is a superfinishing operation performed to improve surface and subsurface integrity. In the present study, a model was developed to confirm that the ball burnishing of AISI 8620 steel affects its microstructures, roughness, and residual stress. As a part of the process, the influence of different parameters on the residual stress surface in the axial direction was investigated. Samples were prepared by heat treatment and turning. The ball-burnishing process was performed, and the improvements on the surface and subsurface integrity were found to be significant. Residual stress after ball burnishing was found to be affected by pressure and feed rate to a statistically significant extent. Stress was found to be in the form of compression. The steel displayed significant improvements in surface roughness and residual stress following burnishing. The linear regression models derived from the data for the relationship between burnishing factors and residual stress offer R2 values of 80.88%. Results suggest that the ball-burnishing process enhanced the properties of AISI 8620 steel.

The influence of ball and roller burnishing process parameters on surface integrity of Al 2024 alloy

Ball and Roller burnishing process is considered as one of the prominent cold working process among post machining operations used as surface treatment method for engineering materials in product design and manufacturing industry. This burnishing process mainly enhances the surface integral properties like compressive residual stresses, surface roughness (in microns) and surface hardness. The intent of this work is to design, develop a ball and deep roller burnishing surface treatment device and also to investigate the surface integral properties like residual stress, surface roughness and hardness of aluminium 2024 alloy before and after burnishing treatment process. The ball and deep roller burnishing process is carried out on aluminium 2024 alloy by varying process parameters like burnishing force, feed, number of burnishing tool passes. The results of experimentation shows that roller burnishing induces beneficial surface roughness, residual compressive stress and ball burnishing provides beneficial hardness.

Surface Texture Analysis after Hydrostatic Burnishing on X38CrMoV5-1 Steel

Ball burnishing is a plastic deformation process used as a surface smoothing and surface improvement finishing treatment after turning or milling processes. This process changes the surface stereometrics of the previously machining surface. Burnishing with hydrostatic tools can be easily and effectively used on both conventional and Computer Numeric Control (CNC) machines. The existing research of the burnishing process mainly focuses on the functional surface characterization, for example, surface roughness, wear resistance, surface layer hardness, etc. There is a lack of references reporting a detailed analysis of 3D parameters calculation with a mathematical model to evaluate the results of the ball burnishing. This paper presents the effect of ball burnishing process parameters with hydrostatic tools on the resulting surface structure geometry. The surface topography parameters were calculated using the TalyMap software. Studies were conducted based on Hartley’s static, determined plan. Such a plan can be built on a hypersphere or hypercube. In this work, a hypercube was used. In the case of Hartley’s plan makes it possible to define the regression equation in the form of a polynomial of the second degree. The input process parameters considered in this study include the burnishing rate, applied pressure, and line-to-line pitch. The significant influence of these parameters was confirmed and described as a mathematical power model. The results also showed a positive effect of hydrostatic burnishing on the roughness and geometric structure of the surface.

Investigation the influence of surface topography on scattering ability of aluminium reflectors from infrared quartz heater

Infrared (IR) heaters are used in many industries where heat treatment is required as well as in household appliances. One of the main problems with this type of equipment is non-uniform temperature field in the heating area, which results in a different degree of heating of the heated objects. In order to achieve greater uniformity of the temperature, some approaches are explored in practice, such as using embossed reflectors, mounting two or more heaters side-by-side, using emitter lamps with power controller devices, formation of gold or silver coatings, etc. The drawbacks of these approaches are complicating the design of the IR heaters, reducing the dimensions of heating area, increasing energy consumption, etc. Among the above-mentioned methods, the creation of a specific reflector surface topography is easily attainable and inexpensive technological approach. The main task of the present study is to investigate experimentally the influence of the specific patterns, obtained by ball burnishing process on scattering ability of the aluminium reflectors from infrared quartz heater.

Optimization of ball-burnishing process parameters on surface roughness, micro hardness of Mg–Zn–Ca alloy and investigation of corrosion behavior

In this work, optimization of ball burnishing parameters (depth of press, feed, burnishing force, number of passes) and their effect on surface roughness, microhardness and corrosion behavior of Mg-4%Zn-1%Ca alloy is investigated. The Taguchi optimization technique was used to determine the number of experiments and by considering S/N ratios, right combination of ball burnishing parameters were selected. Results obtained from the experiments were investigated and it is understood that depth of press, feed and number of passes have a significant effect on surface roughness, microhardness and consequently improves corrosion resistance of Mg-4%Zn-1%Ca alloy. From ball burnishing experiments it is deduced that there is large increase in microhardness of 107 Hv and surface roughness of 129 nm, achieved for the depth of press 0.45 mm, burnishing force 250 N, feed 450 mm min−1 and number of passes: 2. Corrosion behavior of the alloys were analyzed using potentiodynamic polarization and electrochemical impedance spectroscopy techniques in Hank’s balanced salt solution. The lowest corrosion rate was observed in DFN 442 sample (1.43 mm y−1) which is 4.7 times better than the homogenized alloy (6.73 mm y−1). It has been found that the ball burnishing plays an important role on surface roughness, microhardness and corrosion behavior of Mg-4%Zn-1%Ca alloy.

Surface hardening of 36 NiCrMo 6 steel by ball burnishing process

This work aims to characterize the 36 NiCrMo 6 steel in monotic traction. The tested samples were subjected to mechanical surface treatment (MST) by diamond ball burnishing. This process allow it possible to modify the physical and geometrical properties of the material. The stress-strain diagram obtained were processed and digitalised. The hardening domain was modelled and rational curves were established, taking into account the stresses triaxiality. Thus, the work hardening exponent of material considered was evaluated. The effect of ball burnishing on this exponent has studied in proceeding a comparative manner between burnished and machined surface. The results obtained show that by applying the optimal parameters for burnishing, the work hardening exponent of pre-machined surface layer can be increased by 10%, where nB = 0.407 (nT = 0.312 machined surface).

Joining metrics enhancement when combining FSW and ball-burnishing in a 2050 aluminium alloy

This report describes the effect of the ball-burnishing process on the mechanical properties of 2050 aluminium alloy that was previously friction stir welded. This process is a fast, environmentally-friendly and cost-effective surface treatment based on the plastic deformation of the surface irregularities. Consequently, residual stress, material hardening and micro-structural alterations are investigated to improve fatigue strength and wear resistance. The results show that the ball-burnishing treatment enhances the surface properties by increasing the material hardness about 37.5% and by decreasing the average surface roughness from 2.23 μm to 0.06 μm when a high pressure and a perpendicular burnishing is deployed. Additionally, in-depth compressive residual stresses are generated from −315 MPa to −700 MPa depending on the burnishing configuration. Finally, a numerical simulation of the material elastoplastic response is performed to analyze the residual stress continuity in the cross sectional area when using two radial feeds and burnishing pressures. In short, the present study helps to reduce time consumption by selecting the larger radial feed combined with a proper burnishing pressure to ensure the desired quality and compressive residual stress at the surface, which are indices of enhancing the fatigue strength at the nugget zone of the welded area.

Experimental research and ANN modeling on the impact of the ball burnishing process on the mechanical properties of 5083 Al-Mg material

Experimental research and ANN modeling on the impact of the ball burnishing process on the mechanical properties of 5083 Al-Mg material

Impact wear behavior of ball burnished 316L stainless steel

This study investigated the damage mechanism occurring in metallic materials working under repeated impact loads. AISI 316L stainless steel was used as the test material. In order to reduce the impact wear (IW) damage without disturbing the structure of the material, a ball burnishing (BB) process was applied to the workpiece surface. IW tests were carried out in air at ambient temperature and a frequency of 5 Hz under a 560 N (0.12 J) load. This study also investigated the effects of three different cycles on the wear mechanism. As a result of the experiments, the amount of deformation and the volume loss on the surface increased in parallel with the number of impacts. Strain hardening occurred and the surface hardness increased. The IW process affected the surface region to a depth of 360 μm. According to the metallographic observations, the wear mechanism occurred in the form of delamination and flake like spalling. The BB process reduced IW induced volume loss between 62% to 53%.

Near surface transformations of stainless steel cold spray and laser cladding deposits after turning and ball-burnishing

An experimental study is performed to assess the surface integrity of cold sprayed and laser cladded 17-4PH stainless steel deposits after turning and ball-burnishing. A special emphasis is given to near surface microstructure and residual stress distribution. It is shown that both cold spray and cladding deposits could be machined under cutting conditions close to those employed for a conventionally rolled 17-4PH stainless steel. Analysing the resulting microstructure in the near-surface revealed that the turning and ball-burnishing processes affect the coating surface and generate a thin layer where the microstructure can be hardly identified. Residual stress measurements by an X-ray diffraction method revealed that turning results in tensile residual stresses in the near-surface of both the cold spray and laser cladding deposits. Surface treatment by ball-burnishing can be significantly beneficial as compressive residual stresses were measured in both coatings in the near-surface zone but to a larger extent in the cladded material. The comparison of the two profiles showed that the cutting and deformation mechanisms can be significantly different depending on the intrinsic nature of the deposited microstructure.

Influence of Ball-Burnishing Process on Surface Topography Parameters and Tribological Properties of Hardened Steel

The ball-burnishing process is a particular finishing treatment that can improve selected properties of different materials. In the present study, the ball-burnishing technique was used to investigate the effect of input parameters of processes on selected surface layer features like surface roughness and residual stresses of the 42CrMo4 steel surfaces. The burnishing process was conducted on Haas CNC Vertical Mill Center VF-3 using a tool with tungsten carbide tip. A further objective of our research was to improve tribological properties of the aforementioned steel by the ball-burnishing process. The results of the investigations showed that it was possible to reduce the root mean square height of the surface Sq from 0.522 μm to 0.051 μm and to increase wear resistance compared to ground samples.

An Experimental Study on the Surface Finish of Ball Burnished Magnesium (Rare Earth base) Alloy

Abstract Ball burnishing process is a surface modification technique that improves the surface finish, microhardness and induces compressive residual stress on the surface and sub-surface of manufactured parts. As a result, the service life is enhanced with the improvement of wear, corrosion, fatigue and creep resistance. This paper focused on the ball burnishing of rare earth based Magnesium Ze41A alloy and also studied the effect of burnishing force, lateral feed and no. of passes on the surface finish. Burnishing force of 50 N, lateral feed of 50 μm and 2 pass condition provides the better surface roughness results..

BALL BURNISHING PROCESS EFFECTS ON SURFACE ROUHGNESS FOR Al 6013 ALLOY

Ball burnishing process rapidly developing and applied in many applications. The process's advantageous aspects on the material increase the quality of the product surface. In this study, a surface quality research was made on 6013 series of aluminum alloys which are used frequently in the industry. As a result of the experiments, it was seen that the ball burnishing process increased the surface qualities extremely. At the same time, the results obtained were mathematically analyzed.

A Review on Ball, Roller, Low Plasticity Burnishing Process

Abstract The demand for more and more highly finished surfaces has become an important and mandatory characteristic for a product or machine. These characteristics can be achieved by burnishing operation where the surface roughness of parts is reduced to the maximum extent. The reduction in surface finish on the work piece involves plastic deformation of materials and cold working process. This paper presents a review on Low Plasticity Burnishing (LPB), ball burnishing and roller burnishing processes and the work carried out by various researchers in these areas. From the literature it is identified that the LPB approach enhances the fatigue strength, surface finish, surface micro hardness, thermal stability and different damage mechanics like fracture of dynamics, corrosion fatigue and fretting fatigue, burnishing mechanics, properties such as contact stresses, residual stresses and improves HCF performance. These three burnishing processes with various input parameters are like burnishing pressure, speed and feed rate, burnishing force, ball material were compared and analyzed with respect various surface characteristics of the specimen.

Determining the effect of ball burnishing parameters on surface roughness using the Taguchi method

Abstract Burnishing is a low-cost surface treatment process and can be used efficaciously to reduce the surface height and increase of the surface hardness of a workpiece. Low surface roughness and good fatigue behaviours of some engineering components are becoming now more important. Main applications are automotive crankshaft, inner and outer bearings races, bogies axles, etc. Ball burnishing process parameters such as burnishing speed, burnishing feed, burnishing force and burnishing width were considered to minimize the surface roughness. The ball burnishing experiment were planned as per L9 orthogonal array and signal to noise (S/N) ratio was applied to measure the proposed performance characteristics. The significance of the parameters on characteristics of the hydrostatic burnishing process have been evaluated quantitatively with the analysis of variance method.