scholarly journals The Effects of Wear upon the Axial Profile of a Grinding Wheel in the Construction of Innovative Grinding Wheels for Internal Cylindrical Grinding

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
K. Nadolny ◽  
B. Słowiński
Keyword(s):  
Removal Rate ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Cylindrical Grinding ◽  
Single Pass ◽  
Grinding Processes ◽  
Sintered Corundum ◽  
Internal Cylindrical Grinding ◽  
Axial Profile ◽  
Grinding Power

The article describes the effects of wear upon the axial profile of a grinding wheel in the axial cylindrical grinding processes. This mechanism was used to develop a grinding wheel with zone diversified structure made of microcrystalline sintered corundum abrasive grains and vitrifies bond. Such a grinding wheel is characterized by the conical rough grinding zone that is made by grains of a relatively large size, and a cylindrical finish grinding zone with grains of a smaller size and can be used in the single-pass grinding processes. Investigative tests conducted using newly-developed grinding wheels were described. Investigations were operated in the single-pass internal cylindrical grinding process of 100Cr6 steel. A comparison of results obtained using a zone diversified structure grinding wheel, with reference to a grinding wheel with grains of one size, were given. The analysis provides the roughness of the grinded surface, the grinding power, as well as chosen indicators of grinding efficiency. Experimental results obtained with use of a zone-diversified grinding wheel, built from relatively cheap grains of microcrystalline sintered corundum, showed that it is possible to obtain large material removal rate up to approximately 24 mm3/s and high quality of machined surface ( μm).

Development in the Dressing of Super Abrasive Grinding Wheels

2009 ◽  
Vol 404 ◽  
pp. 1-10 ◽  
Author(s):  
Berend Denkena ◽  
Luis de Leon ◽  
B. Wang ◽  
Dennis Hahmann
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Fine Grained ◽  
Grinding Processes ◽  
Shifting Strategy ◽  
Contact Discharge

Harder workpiece materials and increased efficiency requirements for grinding processes make the use of super abrasive grinding wheels indispensable. This paper presents newly developed processes for the dressing of super abrasive grinding wheels. The different bond systems of grinding wheels require distinct dressing process. In this paper, dressing processes for metal and vitrified bonded grinding wheels are investigated. It introduces the method of electro contact discharge dressing for the conditioning of metal-bonded, fine-grained multilayer grinding wheels. A description of the essential correlation between dressing parameters and the material removal rate of the bond material is presented. The considered parameters are the dressing voltage, the limitation of the dressing current and the feed as well as the infeed of the electrode. For the grinding of functional microgroove structures, multiroof profiles with microscopic tip geometries are dressed onto the grinding wheel. For this, a profile roller in combination with a special shifting strategy is applied on finegrained vitrified bonded grinding wheels.

The effect of active surface morphology of grinding wheel with zone-diversified structure on the form of chips in traverse internal cylindrical grinding of 100Cr6 steel

2016 ◽  
Vol 232 (6) ◽  
pp. 965-978 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Wojciech Kapłonek ◽  
Grzegorz Królczyk ◽  
Nicolae Ungureanu
Keyword(s):  
Surface Morphology ◽  
Active Surface ◽  
Experimental Investigations ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Electron Microscopic ◽  
Cylindrical Grinding ◽  
Scanning Electron Microscopic ◽  
Internal Cylindrical Grinding ◽  
Traverse Grinding

The article presents the results of experimental investigations to determine the effect of active surface morphology of grinding wheels with a zone-diversified structure on the form and size of chips generated during traverse internal cylindrical grinding of 100Cr6 steel. In the grinding process involving grinding wheels with a zone-diversified structure, chip formation phenomena differ in the rough and finish grinding zones of the tool. In order to expand one’s knowledge of this phenomena, the microtopography measurements of the grinding wheel active surface in the rough and finish grinding zones were made, as well as scanning electron microscopic observations of these areas after the dressing cut and following internal cylindrical traverse grinding. The conducted studies showed that chips in the rough grinding zone of the grinding wheel active surface are usually several hundred micrometers in length. In the finish grinding zone, however, mainly micro-chips were generated whose length does not exceed 100 µm (usually around 10 µm in length). In the rough grinding zone, shearing-type and flowing-type chips dominate with a few examples of spherical melted chips. Moreover, in the finish grinding zone, mainly slice-type and knife-type micro-chips were observed.

scholarly journals Experimental Studies on the Centrifugal MQL-CCA Method of Applying Coolant during the Internal Cylindrical Grinding Process

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2383 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Seweryn Kieraś
Keyword(s):  
Hybrid Method ◽  
Experimental Studies ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Cylindrical Grinding ◽  
Minimum Quantity ◽  
Dry Grinding ◽  
Internal Cylindrical Grinding ◽  
Cooling And Lubrication

This paper presents the results of experimental research concerning the possibility of supporting the cooling function during internal cylindrical grinding using the minimum quantity lubrication (MQL) method by additional delivery of a compressed cooled air (CCL) stream. The article presents a description of a hybrid method of cooling and lubrication of the grinding zone integrating centrifugal (through a grinding wheel) lubrication with the minimum quantity of lubricant and cooling with a compressed cooled air stream generated by a cold air gun (CAG). The methodology and results of experimental studies are also presented in detail, with the aim of determining the influence of the application of the hybrid method of cooling and lubrication of the machining zone on the course and results of the internal cylindrical grinding process of 100Cr6 steel in comparison with other methods of cooling and lubrication, as well as compared with dry grinding. The research results obtained using the described hybrid method of cooling and lubrication of the grinding zone are related to the results obtained under the conditions of centrifugal MQL method, cooling with a stream of CCA, cooling and lubrication with a stream of oil-in-water emulsion delivered using the flood method, and dry grinding. The efficiency of the grinding process is evaluated (based on the average grinding power Pav, grinding wheel volumetric wear Vs, material removal Vw, and grinding ratio G), along with the thermal conditions of the process (based on the analysis of thermograms recorded by infrared thermal imaging method), the textures of machined surfaces (based on microtopography measured by contact profilometry), the state of residual stress in the surface layers of workpieces (determined by X-ray diffraction method), and the state of the grinding wheels’ active surfaces after grinding (based on microtopography measured by laser triangulation and images recorded with a digital measuring microscope). The obtained results of the analyses show that the application of the hybrid method allows for the longest wheel life among the five compared grinding methods, which is about 2.7 times the life of grinding wheels working under the flood cooling and centrifugal MQL methods, and as much as 8 times the life of grinding wheels working under the conditions of CCA only and dry grinding.

scholarly journals Simulation Studies on Centrifugal MQL-CCA Method of Applying Coolant during Internal Cylindrical Grinding Process

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2506
Author(s):  
Seweryn Kieraś ◽  
Marek Jakubowski ◽  
Krzysztof Nadolny
Keyword(s):  
Coolant Flow ◽  
Grinding Wheel ◽  
Geometrical Parameters ◽  
Grinding Process ◽  
Simulation Studies ◽  
Cylindrical Grinding ◽  
Supply Line ◽  
Air Gun ◽  
Internal Cylindrical Grinding ◽  
Cooling And Lubrication

This paper describes simulation studies regarding the application of the centrifugal minimum quantity lubrication (MQL) method simultaneously with the delivery of a compressed cooled air (CCA) stream in the internal cylindrical grinding process. The idea of a new hybrid cooling and lubrication method connecting centrifugal (through a grinding wheel) lubrication by MQL with a CCA stream is described. The methodology of computational fluid dynamics (CFD) simulation studies, as well as the results of numerical simulations, are presented in detail. The aim of the simulations was to determine the most favourable geometrical and kinematic parameters of the system in the context of air-oil aerosol and CCA flow, as well as heat exchange. In the simulation, the variables were the grinding arbor geometrical parameters, the angle of CCA supply line outlets, and the grinding wheel and workpiece peripheral speed. As a result of the simulation studies, the most favourable geometrical parameters were designated, determining the orientation of the ends of the two CCA supply line outlets before and after the grinding zone, the number of openings in the drilled-out grinding arbor, and the influence of the grinding speed on the parameters of the coolant flow and temperature of objects in the grinding zone. In addition, the results of simulation tests made it possible to visualise the velocity vectors of the two-phase coolant flow in a complex system of air-oil aerosol delivery centrifugally through an open structure of a very fast rotating porous layer (grinding wheel), with an additional supply of CCA using an external cold air gun (CAG).

scholarly journals Internal Cylindrical Grinding Process of INCONEL® Alloy 600 Using Grinding Wheels with Sol–Gel Alumina and a Synthetic Organosilicon Polymer-Based Impregnate

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 115 ◽  
Author(s):  
Wojciech Kapłonek ◽  
Krzysztof Nadolny ◽  
Krzysztof Rokosz ◽  
Jocelyne Marciano ◽  
Mozammel Mia ◽  
...  
Keyword(s):  
Sol Gel ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Alloy 600 ◽  
Abrasive Tool ◽  
Grinding Wheels ◽  
Impregnation Process ◽  
Organosilicon Polymer ◽  
Internal Cylindrical Grinding ◽  
Abrasive Tools

The development of modern jet engines would not be possible without dynamically developed nickel–chromium-based superalloys, such as INCONEL® The effective abrasive machining of above materials brings with it many problems and challenges, such as intensive clogging of the grinding wheel active surface (GWAS). This extremely unfavorable effect causes a reduction in the cutting ability of the abrasive tool as well as increase to grinding forces and friction in the whole process. The authors of this work demonstrate that introduction of a synthetic organosilicon polymer-based impregnating substance to the GWAS can significantly improve the effects of carrying out the abrasive process of hard-to-cut materials. Experimental studies were carried out on a set of a silicon-treated small-sized sol–gel alumina 1-35×10×10-SG/F46G10VTO grinding wheels. The set contained abrasive tools after the internal cylindrical grinding process of INCONEL® alloy 600 rings and reference abrasive tools. The condition of the GWAS after the impregnation process was studied, including imaging and measurements of its microgeometry using confocal laser scanning microscopy (CLSM), microanalysis of its elemental distribution using energy dispersive X-ray fluorescence (EDXRF), and the influence of impregnation process on the grinding temperature using infrared thermography (IRT). The obtained results confirmed the correctness of introduction of the impregnating substance into the grinding wheel structure, and it was possible to obtain an abrasive tool with a recommended characteristic. The main favorable features of treated grinding wheel concerning the reduction of adhesion between the GWAS and grinding process products (limitation of the clogging phenomenon) as well as reduction of friction in the grinding process, which has a positive effect on the thermal conditions in the grinding zone.

Factors Influencing the Performance of Grinding Wheels

1959 ◽  
Vol 81 (3) ◽  
pp. 187-199 ◽  
Author(s):  
E. J. Krabacher
Keyword(s):  
Metal Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Metal Removal Rate ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Grinding Wheel Wear ◽  
Grinding Ratio ◽  
Material Hardness ◽  
Chip Load

Optimum utilization of grinding wheels can best be achieved if the nature of their performance and wear characteristics, and the factors that affect these characteristics, are understood and applied. As reported in this paper, a comprehensive, continuing, grinding-research program has contributed to such an understanding. A study of the nature of grinding-wheel wear indicates that the grinding-wheel wear curve is similar to those of other cutting tools. It demonstrates further that the type of grinding operation significantly affects the nature of wheel wear. A unique technique has been developed for very accurately measuring grinding-wheel wear. This measured wear may be translated into terms of “grinding ratio,” which is the generally accepted parameter for measuring wheel wear. It is the ratio of the volume of metal removed per unit volume of wheel worn away. Extensive studies have been carried out to determine the effect of mechanical variables on grinding ratio, power required in metal removal, and on surface finish. Experimental findings indicate that grinding ratio decreases with increased metal-removal rate and increases with workpiece diameter, decreased chip load, and increased concentration of grinding fluid. Power is found to increase with both the metal-removal rate and the amount of metal removed. It increases slightly with workpiece diameter and is affected little by work-material hardness. Surface finish is found to improve with decreased metal-removal rate and decreased chip load. It also is affected little by work diameter or work-material hardness. Fundamental research in the mechanics of wheel wear is supplying much additional information in the study of grinding-wheel wear. The measurement of grinding forces employing a cylindrical grinding dynamometer provides the opportunity for relating the wear of grinding wheels to the basic mechanics of the process through such fundamental quantities as grinding forces, specific energy, and grinding friction. Two additional experimental techniques for the study of chip formation in grinding have also proved to be most useful research tools. A “quick-stop” apparatus is used to freeze the grinding action by accelerating a tiny workpiece almost instantaneously to grinding-wheel speed. Another technique permits the comparison of the shape of the grinding grit and that of the contour of its path through the workpiece by a unique replicating method.

Potential for improving efficiency of the internal cylindrical grinding process by modification of the grinding wheel structure—Part II: Grinding wheels made of superabrasive grains

2016 ◽  
Vol 231 (4) ◽  
pp. 813-823 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Witold Habrat
Keyword(s):  
Cubic Boron Nitride ◽  
Positive Influence ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Structural Modifications ◽  
Synthetic Diamonds ◽  
Wide Range ◽  
Internal Cylindrical Grinding ◽  
Different Diameters

This article offers an overview of 11 grinding wheel construction modifications used in the peripheral grinding of flat, shaped, internal, and external cylindrical surfaces, when grinding wheels made of superabrasive grains are used (natural and synthetic diamonds, as well as mono- and microcrystalline cubic boron nitride). The text contains characteristics of grinding wheels with: bubble corundum grains, glass-crystalline bond, conic chamfer, zones of different diameters, a centrifugal provision of the coolant into the grinding zone, aggregate grains, zone-diversified structure, as well as impregnated (self-lubricating), multiporous, segment and “intelligent” grinding wheels. Each of the presented structural modifications were described by giving construction scheme, used abrasive grains, range of applications, advantages as well as disadvantages. Modifications of the grinding wheel construction allow for effective improvement of both the conditions and the results of the grinding process. A wide range of the known modifications allow for their proper selection depending on the required criteria of effective evaluation and taking into account the specific characteristics of superabrasive grains. As a result, it is possible to obtain positive influence on a number of technological factors of the grinding process. The described modifications of the grinding wheel structure can be also an inspiration and the basis for creating new solutions in this field.

Optimization and Application of Laser-Dressed cBN Grinding Wheels

2016 ◽  
Vol 1136 ◽  
pp. 90-96 ◽  
Author(s):  
Ali Zahedi ◽  
Bahman Azarhoushang ◽  
Javad Akbari
Keyword(s):  
Environmental Concerns ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Average Roughness ◽  
Cylindrical Grinding ◽  
Laser Dressing ◽  
Dressing Tool ◽  
Cbn Grinding Wheel ◽  
Spindle Power

Laser-dressing has been shown to be a promising method for overcoming some shortcomings of the conventional methods such as high wear of the dressing tool and its environmental concerns, high induced damage to the grinding wheel, low form flexibility and low speed. In this study, a resin bonded cBN grinding wheel has been dressed with a picosecond Yb:YAG laser. The efficiency of the laser-dressed grinding wheels has been compared with the conventionally dressed and sharpened grinding wheels through execution of cylindrical grinding tests on a steel workpiece (100Cr6). The conventional dressing and sharpening processes have been performed by using a vitrified SiC wheel and vitrified alumina blocks, respectively. By recording the spindle power values along with the surface topography measurements of the ground workpieces and the extraction of two roughness parameters (the average roughness Ra and the average roughness depth Rz), it is possible to provide an assessment of the cylindrical grinding process with different dressing conditions i.e. laser-dressing and conventional dressing. Accordingly, a strategy will be proposed to optimize the cylindrical grinding process with laser-dressed wheels regarding the forces and roughness values.

Cylindrical Grinding by Structured Wheels

2016 ◽  
Vol 874 ◽  
pp. 101-108 ◽  
Author(s):  
Amir Daneshi ◽  
Bahman Azarhoushang
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Promising Method ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Cylindrical Grinding ◽  
Dry Grinding

Structuring of the grinding wheels is a promising method to reduce the forces involved in grinding, especially during dry grinding. In this paper, one of the methods of grinding wheel structuring is presented. The structuring process was modeled to find the corresponding dressing parameters for the desired structure dimensions. The cylindrical grinding operation with the structured wheels was simulated to produce a spiral free ground surface. Afterwards, the dry grinding experiments with the structured and non-structured wheels were carried out to evaluate the efficiency of the structured wheels. The results revealed that the grinding forces can be reduced by more than 50% when the grinding wheels are structured, while the surface roughness values increase by 80%.

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