scholarly journals Morphology of Near- and Semispherical Melted Chips after the Grinding Processes Using Sol-Gel Abrasives Based on SEM-Imaging and Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
W. Kapłonek ◽  
K. Nadolny ◽  
W. Habrat
Keyword(s):  
Sol Gel ◽  
Machining Process ◽  
Grinding Wheel ◽  
Geometrical Parameters ◽  
Grinding Process ◽  
Sintered Corundum ◽  
Internal Cylindrical Grinding ◽  
Sem Imaging ◽  
Titanium Grade ◽  
Process Observation

Selected issues related to SEM-imaging and image analysis of spherical melted chips formed during the grinding process are presented and discussed. The general characteristics of this specific group of machining products are given. Chip formation phenomena, as well as their overall morphology, are presented using selected examples of near- and semispherical melted chips occurring singly or concentrated in clusters on the grinding wheel surface after the machining process. Observation of the spherical melted chips and acquisition of their images were carried out for grinding wheel active surfaces with microcrystalline sintered corundum abrasive grains SG™after the internal cylindrical grinding process of a 100Cr6 steel and Titanium Grade 2® alloy by use of a scanning electron microscope, JEOL JSM-5500LV. Analysis of the obtained SEM micrographs was carried out by Image-Pro® Plus 5.0 software to determine the selected geometrical parameters describing the morphological features of the assessed chips.

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.

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

2016 ◽  
Vol 231 (4) ◽  
pp. 621-632 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Witold Habrat
Keyword(s):  
Sol Gel ◽  
Active Surface ◽  
Positive Influence ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Abrasive Grains ◽  
Wide Range ◽  
Internal Cylindrical Grinding ◽  
Different Diameters

This article offers an overview of 14 grinding wheel construction modifications used in the peripheral grinding of flat-shaped internal and external cylindrical surfaces, when grinding wheels made of conventional abrasive grains are used (Al2O3, sol-gel alumina, SiC, etc.). The text contains characteristics of grinding wheels with mixed grains, glass-crystalline bond, a centrifugal provision of the coolant into the grinding zone, aggregate grains, zones of different diameters, radial rough grinding zone, extended finish grinding segments, active surface macro- and micro-discontinuities, as well as multiporous, impregnated (self-lubricating), sandwich, sectional and segment grinding wheels. Each of the presented structural modifications was 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 allows for their proper selection depending on the required criteria of effective evaluation and taking into account the specific characteristics of conventional abrasive 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.

scholarly journals Modeling and Simulation of Process-Machine Interaction in Grinding of Cemented Carbide Indexable Inserts

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Feng ◽  
Bin Yao ◽  
BinQiang Chen ◽  
DongSheng Zhang ◽  
XiangLei Zhang ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Dynamic Instability ◽  
Process Models ◽  
Cemented Carbide ◽  
Machining Process ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Machine Model ◽  
Machine Interaction ◽  
Process Machine Interaction

Interaction of process and machine in grinding of hard and brittle materials such as cemented carbide may cause dynamic instability of the machining process resulting in machining errors and a decrease in productivity. Commonly, the process and machine tools were dealt with separately, which does not take into consideration the mutual interaction between the two subsystems and thus cannot represent the real cutting operations. This paper proposes a method of modeling and simulation to understand well the process-machine interaction in grinding process of cemented carbide indexable inserts. First, a virtual grinding wheel model is built by considering the random nature of abrasive grains and a kinematic-geometrical simulation is adopted to describe the grinding process. Then, a wheel-spindle model is simulated by means of the finite element method to represent the machine structure. The characteristic equation of the closed-loop dynamic grinding system is derived to provide a mathematic description of the process-machine interaction. Furthermore, a coupling simulation of grinding wheel-spindle deformations and grinding process force by combining both the process and machine model is developed to investigate the interaction between process and machine. This paper provides an integrated grinding model combining the machine and process models, which can be used to predict process-machine interactions in grinding process.

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.

Kinematics Simulation of Grinding Process Based on Virtual Wheel Model and Micro-Cutting Analysis

2009 ◽  
Author(s):  
Xuekun Li ◽  
Yiming Kevin Rong
Keyword(s):  
Surface Condition ◽  
Machining Process ◽  
Iteration Step ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Surface ◽  
Grinding Processes ◽  
Kinematics Simulation ◽  
Wheel Model ◽  
Grinding Conditions

Grinding is a special machining process with large number of parameters influencing each other. Any grinding process involves six basic microscopic wheel-workpiece interaction modes in terms of grain cutting, plowing, and sliding, as well as bond-workpiece friction, chip-workpiece friction, and chipbond friction. And quantification of all the 6 modes immensely enhances understanding and managing of the grinding processes. In this paper, the kinematics simulation is presented to imitate the grinding wheel surface moving against the workpiece under specified grinding conditions. The grinding wheel surface is imported from the fabrication analysis based grinding wheel model of previous work. During each simulation iteration step, it provides the number of contacting grains, contact cross-section area for each grain, and resultant workpiece surface condition. Through retrieving the specific force value from the single grain cutting simulation, the cutting force and plowing force can be calculated. This model can also be potentially used in the time dependent behavior and thermal analysis of grinding processes.

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 Experimental Studies on MoS2-Treated Grinding Wheel Active Surface Condition after High-Efficiency Internal Cylindrical Grinding Process of INCONEL® Alloy 718

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 255 ◽  
Author(s):  
Kapłonek ◽  
Nadolny ◽  
Sutowska ◽  
Mia ◽  
Pimenov ◽  
...  
Keyword(s):  
High Efficiency ◽  
Surface Condition ◽  
Experimental Studies ◽  
Active Surface ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Abrasive Tool ◽  
Alloy 718 ◽  
Cylindrical Grinding ◽  
Internal Cylindrical Grinding

This work demonstrates that molybdenum disulfide can be successfully used as an impregnating substance that is introduced in the abrasive tool structure for improving its cutting properties and favorably affecting the effects of the abrasive process. For the experimental studies, a set of MoS2-treated small-sized grinding wheels with a technical designation 1-35×10×10×109A5X60L10VE0 PI-50 before and after the reciprocating internal cylindrical grinding process of rings made from INCONEL® alloy 718 was prepared. The condition of grinding wheel active surface was analyzed using an advanced observation measurement system based on stylus/optical profilometry, as well as confocal and electron microscopy. 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 given characteristic.

scholarly journals The Effects of Structured Grinding Wheel Designed Parameters On The Geometries of Ground Structured Surfaces

2021 ◽  
Author(s):  
Amr Monier ◽  
Bing Guo ◽  
Qingliang Zhao ◽  
Zhenfei Guo ◽  
Tamer S. Mahmoud ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Geometrical Parameter ◽  
Simulation Models ◽  
Grinding Wheel ◽  
Geometrical Parameters ◽  
Grinding Process ◽  
Surface Geometry ◽  
Structured Surfaces ◽  
Simulation Results ◽  
Grinding Operations

Abstract This study investigates the effects of the structured wheels’ geometrical parameters on the geometries of structured surfaces machined by grinding operations. First, the geometrical parameters of the structured wheels were determined. The resultant geometrical parameters of structured surfaces were defined and related to the designed operating condition, including the structured wheel and grinding process by mathematical and simulation models. The results showed that each wheel’s geometrical parameter affects the structured surface geometry at different rates. Grinding experiments were then performed to explore experimentally how the geometrical parameters of the structured wheel affect the geometry of structured surfaces and verify the modeling and simulation results and explanations. The results showed a remarkable compatibility between the predicted and machined surfaces and reflected the accuracy of the presented method for machining the structured surfaces by grinding.

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