Showing papers on "Roller burnishing published in 2010"

Finishing of Thermally Sprayed Tool Coatings for Sheet Metal Forming Operations by Roller Burnishing

Abstract: Processing high strength sheet metal materials causes high tribological loads to the surface of forming tools. To increase the wear resistance and therewith the service time of tools, surface coatings containing hard materials are applied by thermal spraying. In the initial “as sprayed” state, the coatings show a rough surface and porous structure, which is not suitable for sheet forming tools. This article describes the finishing of the coatings by subsequent roller burnishing. By the rolling process surface asperities of the coating are flattened and the contact area between the finished surface and the sheet is increased. Furthermore, residual compressive stresses in the surface zone are generated by the rolling process. The tribological properties of the coated and finished surfaces are analyzed in strip drawing tests with uncoated DP600 sheets varying the contact pressure and drawing velocity. It is shown that the process parameters of the roller burnishing process have a strong influence on the surface topology of the friction elements and their tribological properties. The coated and finished friction elements are compared to conventional grinded steel friction elements, made of C60.

Estimation of the Influence of Burnishing Parameters on X5CrNi18-10 Steel

Abstract: Angular momentum pumps are very often applied in ships. Because the pumps are operating in hard conditions they are produced from cavitation wear-proof and electrochemical corrosion-resistant materials. The most common damage of pump shaft is neck wear in place where seals are mounted. Burnishing as modern finish plastic tooling method makes it possible to achieve high technological quality of elements. Due to many burnishing advantages, the method was proposed for treatment of angular momentum pumps shafts instead of finish machining (finish turning, grinding, lapping). The goal was to estimate optimal burnishing parameters that enable obtaining higher strength and the lowest roughness factor of angular momentum pumps shafts. Shaft necks were made of stainless steel type X5CrNi1810. Roller burnishing tool SRMD type produced by Yamato was used in the research work. Its axis was parallel to working shaft axis. During working, technological parameters such as force, velocity and feed were changed.

Surface Characteristics Modification of Polyoxymethylene and Polyurethane Using Burnishing

Abstract: The surface characteristics of polymers play an important role in unlubricated sliding applications that involve a polymer–metal interface because they are relatively softer than most metals. In this article, roller burnishing is introduced as a technique to improve the friction and wear characteristic of polymers in such applications. The polymers used in this study are polyoxymethylene (POM) as a thermoplastic polymer and polyurethane (PUR) as a thermosetting polymer. The combination of moderate values of burnishing force and speed is recommended during burnishing operations. The lowest surface roughness value, R a , achieved for POM is 0.53 μm (32% decrease) and for PUR is 0.57 μm (29% decrease). The tribological behavior of the burnished polymers is found to be predominantly related to their surface quality. The lowest coefficient of friction value achieved in this work for POM is 0.24 (26.8% decrease) for POM and for PUR it is 0.27 (17.7% decrease). The lowest specific wear rate achieved in this work...

An investigation of machining efficiency of internal roller burnishing

Abstract: Purpose: of this paper is investigation of fine machining efficiency of 34CrMo4 steel with roller burnishing tools. Application of roller burnishing process as a clean and environmentally friendly machining process which can replace other pollution processes is of great interests. It is important to evaluate the influence of material properties (primary hardness) for smoothing efficiency and achieving of lower roughness and higher work piece hardness. Design/methodology/approach: Experimental tests of cutting outputs have been done on specimens prepared for final machining process to estimate the rate of roughness decrease, and diameter increase. Roughness measured data before and after roller burnishing process have been compared. Findings: It was found that surface roughness is significantly lower after roller burnishing. Roughness ratio (before/after process) and decrease factor was 4 what doesn’t satisfy expected results. Some roughness results after burnishing exceed upper limits. Research limitations/implications: Results and findings presented in this paper are qualitative and might be slightly different in other machining condition (e.g. higher hardness materials and higher roughness of row material). Practical implications: Smoothing process can be performed on standard machine tools without additional reconfiguration tasks. Process is very rapid. Process is very versatile for any workshop and can be conducted without coolant what is additional advantages for the environment and pollution free machining. Originality/value: Originality of the paper is in analysis of results and smoothing efficiency with Wilcoxon test.

Design and Fabrication of New Type of Dynamometer to Measure Radial Component of Cutting force and Experimental Investigation of Optimum Burnishing force in Roller Burnishing Process

Abstract: In this work, an attempt has been made to design and fabricate a new type of dynamometer to measure radial component of cutting force using strain gauges Dynamometer is required to measure the components of cutting force in any metal cutting process The dynamometer has been calibrated and tested for performance It is used in roller burnishing experiment on aluminum work piece under various conditions In roller burnishing, a hard roller is pressed against a rotating cylindrical work piece and parallel to the axis of the work piece on lathe Optimum values of burnishing force and the corresponding surface roughness value (R a ) are obtained for different lubricant applications in roller burnishing operation This dynamometer can be manufactured at a low cost and it can be used for tests on lathe in metal cutting laboratories and engineering colleges

Development of Ductile Iron Material, Simulation and Production Technology to Locally Strengthen Castings

Abstract: A lot of innovations in molding and casting technology and also simulation techniques have made ductile iron more and more competitive and it even competes meanwhile against steel forgings. A successful substitution of steel forgings for example is the wheel carrier for a high volume car with the Georg Fischer new ductile iron material 'SiboDur', a ductile iron family with high strength and high elongation at the same time. But there is still a great potential for ductile iron castings to substitute steel forgings, in particular in the automotive industry. One example is the crankshaft for the engine: Quite a lot of gasoline engines are equipped with ductile iron crankshafts, but for instance most of the diesel engines are still running with forged steel cranks. The reason is mostly the belief of design engineers that it is not possible to get similar fatigue limit with castings com-pared to forged steel. This belief may often be correct, but using local strengthening technologies, such as roller burnishing of bearing fillets or inductive hardening of highly stressed areas can raise the fatigue limit of casted crankshafts dramatically. The paper presents studies which show that using the right ductile iron material and optimized roller burnishing conditions can raise the fatigue limit of cast crankshafts to values even higher than forged steel ones (material 38MnVS6). But even quenched and tempered forged steel crankshafts are in the focus to be substituted by castings. It is well known that ductile iron also can be induction hardened, but the induction hardening of ductile iron is still an empirical technology. This leads to the second part of the paper: In a cooperation of Georg Fischer and RWP a research project was carried out to develop a simulation technology to predict the residual stresses in a cast crankshaft due to induction hardening under different condi-tions. The results are very encouraging and enable us today to predetermine the induction hardening conditions to get optimized fatigue behavior of ductile iron crankshafts. Of course, the findings can also be used for other applications than crankshafts.

A new single-roller burnishing technique decreasing roughness obtained

Abstract: This article presents outcomes from comprehensive study of a new single-roller burnishing technique of external cylindrical surfaces, directed to achieving smaller roughness of workpieces made of low alloyed constructional steel. The method differs from the conventional roller burnishing because it is performed in conditions of tangential and axial skid between the deforming roller having toroidal operating surface and the workpiece being burnished. This positive effect for roughness has been achieved by a single-roller burnishing device, allowing crossing of the roller and the burnished workpiece axes, as well as adjusting the

Cylinder bore and method for manufacturing the same

Abstract: Provided are a cylinder bore capable of sufficiently removing a cast hole without occurrence of distortion, and thereby realizing improved durability, and a method for manufacturing the same. A cast hole 11A generated during casting is present on the sliding surface 11 of the cylinder bore 10 and in the vicinity thereof. By performing plastic working on the sliding surface 11 of the cylinder bore 10, the cast hole 11A is crushed and the sliding surface 11 of the cylinder bore 10 is smoothed. In plastic working, it is preferable to use a roller burnishing method. Subsequently, a coating 12 having high seizure resistance is formed on the sliding surface 11 of the cylinder bore 10. It is preferable to use a DLC film as the coating 12. By using a material having seizure resistance as the coating material, the degree of freedom of the property of the sliding surface can be improved, and thus the above smoothing can be achieved. [Selection] Figure 1

Brightness hot galvanizing method

Abstract: The invention relates to a brightness hot galvanizing method, comprising the steps of pre-treatment, hot galvanizing, centrifuging and cooling steps in sequence. The method also comprises a polishing step, in which, glass balls with diameter of between 1 and 5mm and deionized water are adopted to perform roller burnishing on a hot galvanized product in a roller for 1 to 5 minutes. The polishing step is added after post-treatment, so the method can remove zinc dust on the surface, partial thread adhesive zinc and zinc residues to greatly improve surface condition, effectively control the dispersion degree of the surface friction coefficient, effectively control the torque coefficient of a steel structured connection pair, and improve the installation performance of the steel structured connection pair.

Flame spraying "Roto-Teck 80" of Ni-Al and Ni-Al-Al2O3 coatings surface texture after roller burnishing

Abstract: The process of flame sprayed is a technology affordable and easy to implement It does not require great skill of the operator This method is not associated with expensive workstation equipment It may therefore be used with success for the regeneration of machine parts by the crew of vessel engine room Flame sprayed coatings are characterized by porosity, oxide inclusions presence and large real area of surface In order to obtain adequate surface roughness coatings must be applied finishing For this purpose, the turning and grinding are used In the paper a burnishing to finishing flame sprayed coatings was proposed Burnishing is not used during the processing of thermally sprayed coatings, as is commonly believed that this technology causes damage to coatings Coatings of Ni-5% Al and Ni-5%Al-15%Al2O3 obtained by powder flame spraying were studied Torch of “RotoTeck 80” was used After turning the average value of surface coatings roughness coefficient Ra = 3 �� m was obtained SRMD burnishing tool produced by “Yamato” company was used Roller burnishing was performer on engine lathe It was found that the increase in burnishing force and the reduction of burnishing speed and feed rate of less roughness of coatings are obtained For Ni-5%Al coatings the lowest surface roughness, Ra = 03 �� m was obtained after burnishing with the following parameters: the force - 1100 N, rate - 28m/min, feed - 008 mm/rev During burnishing of Ni-5% Al-15% - Al2O3 coatings applied force 700 N, Ra = 1 �� m was obtained Greater burnishing force caused coatings damage Burnishing compared to turning has positive influence on the curve shape of the material ratio It was found that the parameters Rk, Rpk and Rpk were reduced

Notice of Retraction Improving quality amp; manufacturability by Design for Six Sigma

Abstract: In this paper, a new Design for Six Sigma(DFSS) integrating Artificial Neural Network approach is presented for improving quality and manufacturability simultaneously. Followed the neural network based on optimal DFSS method is employed as a tool in cutting parameters optimization. The results showed the roller burnishing formation can be controlled by adjusted cutting parameters with DFSS. The experiments proved the roller burnishing size with quality assurance method improved as much as 71 to 79 % comparing with conventional cutting condition. As a matter of fact, the parameters optimization by DFSS method is offering an effective tool to control the roller burnishing size in machining.

Roller burnishing apparatus equipped with pressure sensing device

Abstract: PURPOSE: A roller burnishing apparatus with a pressure detecting device is provided to raise fatigue strength by smoothly finishing the surface of a workpiece and generating compressive residual stress. CONSTITUTION: A roller burnishing apparatus comprises a first and second members, a burnishing roller(86), a pushing device and a pressurizing-force detection device. The first member relatively moves with respect to a workpiece. The second member relatively moves along the relative movement direction of the first member. The burnishing roller is rotatably supported on the second member. The pushing device pushes the first and second members toward the relative movement direction. The pressurizing-force detection device detects the pressure of the burnishing roller to the workpiece based on the pushing force of the pushing apparatus.

Housing for a roller-burnishing tool having an adjustable width

Abstract: The invention relates to a housing (101) for a roller-burnishing tool (100) that comprises two portions (110, 120). According to the invention, the two portions of the housing are located and positioned at a distance from each other using adjustable spacing means (130).

Improvement in the Scratch Resistance of Polymers by Roller Burnishing Process

Abstract: The ability of engineering polymers to resist scratching action has rapidly become a vital requirement for diverse industrial applications because scratches may greatly reduce the life cycle of the components. Therefore, the present work aims to study the possibility of using roller burnishing process to enhance the scratch resistance of polymers to a single pass scratching action. The effects of burnishing feed rate and roller contact width on the scratch hardness of poly(oxymethylene) and polyurethane were considered. The results revealed that low burnishing feed rate and smaller roller contact width led to an increase in scratch hardness for both polymers. The scratch fractures were also observed using SEM to study the changes in wear modes.