Showing papers on "Roller burnishing published in 2017"

Optimization of roller burnishing process on EN-9 grade alloy steel using response surface methodology

Abstract: The roller burnishing tool is used in computer numerical control lathe to superfinish the turning process. The tool and workpiece materials considered are tungsten carbide (69 HRC) and EN-9 Grade Alloy Steel (10 HRC), respectively. The input parameters are burnishing force, feed, roller contact width and number of passes. The response surface methodology is used to develop a mathematical model and optimize the parameters for the surface characteristics (such as surface roughness and surface hardness). The optimum surface roughness and its surface hardness are 0.2 µm and 18 HRC, respectively. The surface roughness is reduced by 94.5% and hardness is improved by 41.7%. The contributing variable of each parameter is estimated using analysis of variance method. The morphology of the burnished surface is investigated using scanning electron microscope.

Optimisation of internal roller burnishing process in CNC machining center using response surface methodology

Abstract: In this study, optimization of the burnishing process was carried out to find better performance of burnishing process in CNC machining center using response surface methodology (RSM). The study was conducted on S.G. cast iron component in DOOSAN vertical machining center using internal roller burnishing tools. The internal roller burnishing tool was used in CNC vertical machining center to maintain precise bore size and surface finish. The input parameters were speed, feed, and penetration allowances for burnishing (stock). In this study, the parameter combinations are made using orthogonal L27 array. The optimization was carried out between input and output parameters for the given constraints using RSM. The response surface mathematical model was developed. The interactions between variables were analyzed using response surface plots. The optimized values for burnishing were burnishing speed of 1100 rpm, burnishing feed of 0.113461 mm/rev, and stock of 0.031503 mm. The optimized bore size (31.74 mm), surface roughness (0.3757 µm), and ovality (0.012 mm) were obtained.

Surface texturing of rolling elements by hard ball-end milling and burnishing

Abstract: Constant velocity joint shafts are machine elements within the driveshaft of cars. The tribological conditions within the raceways are characterized by mixed friction. To improve the lifetime of these machine elements, surface topography and surface integrity have to be adjusted. The positive effect of subsurface compressive residual stresses on the rolling fatigue strength for roller bearings is well known. Additionally, the positive effects of surface textures on tribological conditions in the mixed friction regime are known from cylinder liners. Within this paper, a novel approach to generate tribologically optimized surfaces by hard ball-end milling and an additional mechanical surface treatment by roller burnishing is tested and applied. First, the effects of both processes on the resulting surface topography are analyzed separately. In addition, the interactions between ball-end milling and burnishing are investigated. Concluding, this paper provides parameters to generate a plateau surface by the combination of ball-end milling and roller burnishing.

Burnishing of Al (SiC) p metal matrix composites using TiAlN coated roller

Abstract: Roller burnishing involves plastic deformation by pressing a hard roller against the workpiece. The number of passes, rotational speed of the workpiece and type of lubricant were taken as input parameters. Its effect on surface roughness and surface hardness during burnishing of Al(SiC)p workpiece material was studied. Titanium aluminium nitride (TiAlN) coating was given to the WC rollers with PVD coating and its effects were studied. Roller burnishing of Al(SiC)p MMC can reduce the surface roughness up to 78.84 % and increase surface hardness up to143.4 %. Based on the extrapolated results it is noted that coated rollers under dry conditions produce low surface finish and high hardness.

Performance Improvement of Roller Burnishing Process– A Review

Abstract: This paper presents a review on performance improvement of roller burnishing process. Roller burnishing is a surface finishing process which is economical as compared to other surface finishing process. Roller burnishing along with good quality surface finish also gives improved surface properties. The process parameters mostly considered are burnishing speed, feed rate, number of passes and depth of penetration. Roller burnishing does not require any special arrangement for the process and can be easily carried out on a conventional lathe machine also.

Roller Burnishing Method with Active Rotation Tool - Better Surface Finish than Conventional Roller Burnishing

Abstract: This paper proposes a roller burnishing method that controls the sliding direction of the burnishing tool on the surface of cylindrical workpiece. In this study, the sliding direction was set by inclining the axis of the burnishing tool with respect to the axis of the workpiece and by actively rotating the roller of the burnishing tool. The workpiece was a cylindrical aluminum alloy bar, which was rotated in a bench lathe. The burnished surfaces at several sliding angles between 15º and 90º were evaluated. The sliding direction, which is set according to a theoretical equation, was experimentally obtained for every sliding angle in the range of 15-90º with respect to the circumferential direction of the workpiece. The sectional profile was flattened and surface roughness was decreased with increasing sliding angle. As a result, the burnished surfaces obtained in this work were superior to those obtained in an earlier study by the authors, in which the burnishing tool was not actively rotated.

Effect of Roller Burnishing Parameters on Roughness Surface and Hardness of Unalloyed S 355 J0 Steel by Using Response Surface Methodology

Abstract: Burnishing is a cold working process with superficial plastic deformation, which is to exert an external pressure through a very hard and smooth roller or ball on a surface to occur a uniform and work-hardened surface, to make it possible to reduce roughness, to increase the hardness and to produce residual stresses of compression. The unalloyed S 355 J0 steel specimens were machined on a conventional lathe to the proper dimensions; these machined specimens were then burnished by a simple locally designed and fabricated roller-burnishing tool. The main objective in this work is to determine a mathematical models statistically based on experimental design (response surface methodology) using central composite second-order rotatable design which allows to give the relationship between the two out parameters surface roughness and hardness, representative of the superficial layer surface caused by the four internal roller-burnishing parameters called: burnishing speed, force, feed and number of passes of the tool. The experimental results indicate that feed, burnishing force and speed are the most important and significant parameters to improve roughness surface, and feed, speed, burnishing force and number of passes are the most important and significant parameters to improve superficial hardness of S 355 J0 steel specimens. The surface roughness and hardness were improved from about 2.5μm to 0.15μm and from 176 HV to 226 HV respectively. The validated models with coefficient of determination R2 = 93.1% for surface roughness and R2 = 89.8% for hardness, seem correlate well with the experimental results.

To enhance mechanical properties of parts produced from AlSi10Mg powder with use of SLS/SLM methods by densification of the product surface layer

Abstract: The paper presents results of experiments including application of finish machining (turning and burnishing) of samples produced with SLS/SLM, as well as influence of the sample orientation against the surface of base plate during building process (0°, 45°, 90°) on tensile strength of the produced samples There are also presented results of microstructure examination and results of density measurements The paper also discusses the state of samples surface layer depending on the applied finishing method

Investigation of Roller Burnishing Process on the Mechanical Characteristics, and Micro-hardness of Al-4 wt% Cu Under Hot Work Conditions

Abstract: Burnishing process is a finishing operation that is widely used to increase the fatigue life, wear resistance, and micro-hardness. Roller burnishing processes was used in this work due to its low cost and its simple mechanism. The importance of his study came from the enhancement in the surface layer of Al-4% Cu alloy that translates the tensile stress to compressive stress which is save especially when the material is operated under cyclic loading. A roller burnishing tool was used to investigate the microstructure, micro-hardness and the depth of penetration on Al-4% Cu at 200 °C. It was found that the maximum penetration was 330 µm at 40 N burnishing forces and 0.08 mm/rev feed, Furthermore; the maximum micro-hardness was enhanced by 184.4% at 40 N burnishing force and 0.08 mm/rev feed.

Roller burnishing tool and machining method

Abstract: Provided is a roller burnishing tool capable of burnishing a groove having a narrow width such as an O-ring groove. The roller burnishing tool for machining a surface to be machined on a work is provided with: a roller; a roller pin rotatably supporting the roller; a body having a cavity therein, the body being connected so as to be movable only by a predetermined distance with respect to the roller pin; and a load control unit for controlling a load pressing the surface to be machined that is arranged movably with respect to the body in an axial direction, wherein the roller has a flange part protruding in a direction intersecting an axis of the body and that presses and machines the surface to be machined.

Burnishing method, and roller and roller burnishing tool

Abstract: PROBLEM TO BE SOLVED: To provide a burnishing method capable of suppressing formation of an unworked portion and a worked mark even in a workpiece having an abutting portion (step portion)SOLUTION: A roller 6 has a tip worked portion 6a formed into an arc shape having a radius of curvature of 01 mm or more and 07 mm or less by working a worked surface Wa, and a slid portion 6c which is connected to the tip worked portion 6a and is slid by the worked surface Wa A burnishing method for working the worked surface Wa by pressing a roller 6 against the worked surface includes arranging and working the roller 6 so that a back taper angle formed by the slid portion 6c with respect to the worked surface Wa is 05° or more and 3° or lessSELECTED DRAWING: Figure 2

Effect of Isothermal Annealing Temperatures and Roller Burnishing on the Microhardness and Surface Quality of H13 Alloy Steel

Abstract: AISI H13 tool steel is applied widely to produce many kinds of hot work dies, such as forging dies, extrusion dies, die-casting dies and so on. The successful employment of metal in engineering application relies on the ability of the metal to meet design and services requirements and to be fabricated to the proper dimensions. The capability of metal to meet these requirements is determined by mechanical and physical properties of the metal. Burnishing processes is considered as a surface plastic deformation method, which used to improve surface texture (micro hardness, average surface roughness, and maximum surface roughness). This work present the effect of isothermal annealing temperature and roller burnishing process on the surface properties of H13 alloy steel .This steel was annealed at a different temperatures to get different types of pearlite with different grains and grain size. After that, the steel was burnished with different forces, feeds, and burnishing speeds. The effect of annealing temperatures and roller burnishing on the hardness, micro hardness, average surface roughness and microstructure and metallographic analysis have been investigated. The results showed that roller burnishing could increase the surface hardness under the selected specified conditions depending on the isothermal annealing temperatures by 104%, 45% and 90% for the work parts with 3000C, 500 0C and 6200C annealing temperatures respectively. In addition, roller burnishing significantly improves the smoothness of the steel surfaces. The average roughness obtained was ranged from 0.11μm to 0.17μm. In this paper, the microstructure analysis, micrograph of the isothermal annealed H13 alloy steel have been given. It has been shown that depending on the isothermal annealing temperature there are different types of grains and grain size of treated steel in pearlite phase.

Influence of Abrasives in Roller Burnishing Process on Microhardness Using Factorial Design

Abstract: Burnishing is essentially a cold-working process used to improve properties of the machined surfaces. In present work, an attempt is made to investigate the effect of fine silicon carbide abrasive particles (in the form of a paste) in between roller burnishing tool and cylindrical components of EN24 steel. The mathematical models were developed using 2 4 full factorial design of experiments (DoE) for micro hardness in terms of four variables namely burnishing force, burnishing speed, feed and a number of passes for dry burnishing case and ‘with-paste’ (where burnishing is done using paste) burnishing case. Analysis of variance (ANOVA) is carried out to check the adequacy of the derived models. The results showed that micro hardness of the untreated EN24 steel can be improved by 11% and 18% for dry burnishing case and ‘with-paste’ burnishing case respectively compared to turned components.