Prediction of Blunting Area of Abrasive Grains on a Grinding Wheel

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Aleksandr A. Dyakonov ◽  
Dmitrii V. Ardashev
Keyword(s):  
Cutting Speed ◽  
Mathematic Model ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Abrasive Wheel ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Mass Transfer Theory ◽  
First Time

The article presents the results of calculating the blunting area of abrasive grains of grinding wheels, determined in accordance with the previously developed model. The mathematic model of the size of the blunting area of an abrasive grain considers the main mechanisms of its wear—mechanical and physicochemical. These mechanisms are taken into account in the model. For the first time, the kinetic theory of strength was used for determining the mechanical wear of abrasive grain. The mass transfer theory was used to study the physicochemical wear: coefficients of chemical affinity with the abrasive material are experimentally defined for the assortment of workpiece materials. The developed mathematic model is a multiple-factor one and this will allow to predict the size of wear of the abrasive wheel for different technological conditions. Also, the article presents the experimental method for determining the blunting area of abrasive grains of grinding wheels, which allows making a direct measurement of wear parameters of grinding wheels. The main parameter of grinding wheel wear is the length of the blunting area of the grain, which was measured out in the direction of the cutting speed vector. The grinding wheels of different graininess were studied—F60 and F46. The grinding wheel working surface was studied by numerical photos and microscope. The results of these experiments have confirmed the adequacy of the design model.

scholarly journals An Original Tribometer to Analyze the Behavior of Abrasive Grains in the Grinding Process

2018 ◽  
Author(s):  
Leire Godino ◽  
Iñigo Pombo ◽  
Jose Antonio Sanchez ◽  
Borja Izquierdo
Keyword(s):  
Wear Mechanisms ◽  
Wear Behavior ◽  
Grinding Wheel ◽  
Crystallographic Structure ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Original Design ◽  
Wheel Wear ◽  
Good Tool ◽  
Abrasive Grains

Manufacturing of grinding wheels is continuously adapting to new industrial requirements. New abrasives and new wheel configurations, together with wheel wear control allow for grinding process optimization. However, the wear behavior of the new abrasive materials is not usually studied from a scientific point of view due to the difficulty to control and monitor all the variables affecting the tribochemical wear mechanisms. In this work an original design of pin on disk tribometer is developed in a CNC grinding machine. An Alumina grinding wheel with special characteristics is employed and two types of abrasive are compared: White Fused Alumina (WFA) and Sol-Gel Alumina (SG). The implemented tribometer reaches sliding speeds of between 20 and 30 m/s and real contact pressures up to 190 MPa. The results show that the wear behavior of the abrasive grains is strongly influenced by their crystallographic structure and the tribometer appears to be a very good tool for characterizing the wear mechanisms of grinding wheels, depending on the abrasive grains.

scholarly journals An Original Tribometer to Analyze the Behavior of Abrasive Grains in the Grinding Process

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 557 ◽  
Author(s):  
Leire Godino ◽  
Iñigo Pombo ◽  
Jose Sanchez ◽  
Borja Izquierdo
Keyword(s):  
Wear Mechanisms ◽  
Wear Behavior ◽  
Numerical Control ◽  
Grinding Wheel ◽  
Crystallographic Structure ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Original Design ◽  
Wheel Wear ◽  
Abrasive Grains

Manufacturing of grinding wheels is continuously adapting to new industrial requirements. New abrasives and new wheel configurations, together with wheel wear control allow for grinding process optimization. However, the wear behavior of the new abrasive materials is not usually studied from a scientific point of view due to the difficulty to control and monitor all the variables affecting the tribochemical wear mechanisms. In this work, an original design of pin-on-disk tribometer is developed in a CNC (Computer Numerical Control) grinding machine. An Alumina grinding wheel with special characteristics is employed and two types of abrasive are compared: White Fused Alumina (WFA) and Sol-Gel Alumina (SG). The implemented tribometer reaches sliding speeds of between 20 and 30 m/s and real contact pressures up to 190 MPa. The results show that the wear behavior of the abrasive grains is strongly influenced by their crystallographic structure and the tribometer appears to be a very good tool for characterizing the wear mechanisms of grinding wheels, depending on the abrasive grains.

Observation of Abrasive Grains Behavior in Contact Area of Grinding Wheel and Comparison with Grinding Wheel Model

2008 ◽  
Vol 389-390 ◽  
pp. 48-54
Author(s):  
Taisei Yamada ◽  
Hwa Soo Lee
Keyword(s):  
Contact Area ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Elastic Deformations ◽  
Contact Areas ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Wheel Model

In contact areas between grinding wheels and workpieces, elastic deformations of grinding wheel take place due to the act of grinding forces. Since grinding wheels consist of abrasive grains and bonds, it may be regarded that the elastic deformations of grinding wheels in contact areas depend on movements of each abrasive grain. However, plural grains are connected each other complicatedly, and then it is difficult to observe each grain behavior. This study aims to directly observe the behaviors of grains in contact areas with workpieces. A small loading apparatus for grinding wheel is newly developed. Inserting a loaded wheel with this apparatus into SEM, grains behaviors in contact area are directly observed. Furthermore, grains behaviors under loaded condition are analyzed with a wheel model developed previously and observed results are compared with analyzed results.

Abrasive Grain Efficiency and Surface Roughness in Machining Magnesium Alloys by Newly Developed Cup-Type Diamond-Grinding-Wheels

2009 ◽  
Vol 620-622 ◽  
pp. 769-772
Author(s):  
Tien Dong Nguyen ◽  
Koji Matsumaru ◽  
Masakazu Takatsu ◽  
Kozo Ishizaki
Keyword(s):  
Surface Roughness ◽  
Magnesium Alloys ◽  
Unit Length ◽  
Grinding Wheel ◽  
Light Metals ◽  
Grinding Wheels ◽  
Wheel Surface ◽  
Abrasive Grains ◽  
Diamond Grinding ◽  
Abrasive Grain

New cup-type diamond-grinding-wheels with hexagonal pattern have been developed. Grinding stone ratio, R is defined as the ratio between the hexagonal edge area containing abrasive grains and the total area of the wheel surface. In the present work, four kinds of hexagonal grinding wheels with different R (13 %, 19 %, 25 % and 36 %) and a conventional wheel (R: 100 %) were used to grind a light metals, which was represented by magnesium alloy AZ31B. Efficiency of abrasive grains and ground surface for machining a light metals were evaluated by calculating the number of abrasive grains which pass through a unit length of a sample surface for each grinding pass, Ng. The results show that surface roughness becomes smaller, i. e., smoother surfaces as Ng increases. Surfaces ground by the conventional wheel are rougher than those by using newly developed hexagonal grinding-wheels in spite of the larger Ng for the conventional wheel. Surface roughness data forms one curve in roughness vs. Ng graph for all hexagonal wheels, and forms another curve for the conventional grinding-wheel. The difference of two curves indicates that the number of effective working abrasive grains in hexagonal wheels is about 5 times higher than that of the conventional wheel. The similar results were obtained for machining sapphire according to our previous work. Hexagonal wheels show higher abrasive grain efficiency for machining not only hard-to-machine ceramics but also light metals such as magnesium alloys than conventional wheels.

scholarly journals THE EFFECT OF ABRASIVE GRAIN SHAPES ON QUALITY OF FERRITE MAGNETS GRINDING PROCESS

2020 ◽  
Vol 14 (2) ◽  
pp. 117-124
Author(s):  
Bayu Rahmat Saputro ◽  
Amin Suhadi
Keyword(s):  
Chemical Composition ◽  
Single Layer ◽  
Processing Parameters ◽  
Grinding Process ◽  
Model Design ◽  
Grinding Wheels ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Shape And Size

Abstract A research was conducted on the grinding process of ferrite magnet with Strontium ferrite type (SrO.6 (Fe2O3)) using electroplated single layer grinding wheels. Many cracks have been found on work pieces during this work, which is coming from grinding processes. Research is conducted starting from chemical composition test and the effect of the shape and size of the abrasive grain of grinding wheels to the quality of grinding process results by measuring crack ratio of the work piece.  In this experiment, 3 (three) model design of grinding wheels with three different size and shape of abrasive grains are made. All of processing parameters are set at the same value as ordinary process.  The experimental results shown that 3rd model have the best results from the outputs number and also the lowest reject crack ratio compared to 1st and 2nd models. This is because the 3rd model has blocky shape which its distribution structure is denser and more uniform compared to the irregular shape, so that continuous grinding on hard and brittle work pieces is more stable and suitable

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.

Wear Monitoring on Microcrystalline Aluminum Oxide Grinding Wheels on Profile Grinding with the Aid of Acoustic Emission

2014 ◽  
Vol 894 ◽  
pp. 95-103 ◽  
Author(s):  
Lucas Benini ◽  
Walter Lindolfo Weingaertner ◽  
Lucas da Silva Maciel
Keyword(s):  
Acoustic Emission ◽  
Wear Behavior ◽  
Grinding Wheel ◽  
Wheel Wear ◽  
Profile Grinding ◽  
Grinding Wheel Wear ◽  
Abrasive Grains ◽  
Profile Deviation ◽  
Synthetic Materials ◽  
External Cylindrical Grinding

The localized wear on grinding wheel edges is a common phenomenon on profile grinding since the abrasive grains are less attached to the bond. The grinding wheel wear depends heavily on the process parameters, workpiece and wheel composition, causing changes on the process and profile deviation behaviors. In order to cope with these uncertainties, many natural and synthetic materials have been used in different grinding processes. However, the influence of mixed compositions of different types of abrasive grains on external cylindrical grinding is not well known. In order to assess this relation, a methodology procedure was developed providing an overview of the cinematic edges behavior on a progressive wheel wear. The methodology procedure is based on the acoustic emission technology, using a transducer with a 50 μm radius diamond tip. The tip, when in contact with a rotating grinding wheel, enables the evaluation of the cinematic cutting edges. The abrasive grain density was evaluated for different grinding wheel compositions and specific wear removal values. Furthermore, these results were compared to the profile deviation observed on the same tool, allowing the assessment of the influence of different microcrystalline corundum grains on the overall grinding wheel wear behavior.

Effect of Novel Grinding Wheels on Grinding Performance

2013 ◽  
Vol 405-408 ◽  
pp. 3302-3306
Author(s):  
Ming Yi Tsai ◽  
Shi Xing Jian ◽  
J. H. Chiang
Keyword(s):  
Surface Roughness ◽  
Pure Water ◽  
Minimum Quantity Lubrication ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Grinding Performance ◽  
Conventional Grinding ◽  
Removal Processes

Grinding, a technique for removing abrasive materials, is a chip-removal process that uses an individual abrasive grain as the cutting tool. Abrasive material removal processes can be very challenging owing to the high power requirements and the resulting high temperatures, especially at the workpiece-wheel interface. This paper presents a novel system that uses graphite particles impregnated in an aluminum oxide matrix to form a grinding wheel. This study specifically investigated grinding wheels with a graphite content of 0.5 wt%. The new grinding wheel was compared with conventional grinding wheels by comparing the factors of grinding performance, such as surface roughness, morphology, wheel wear ratio, grinding temperature, and grinding forces, when the wheels were used under two different coolant strategiesdry and with minimum quantity lubrication (MQL) using pure water. This study found that there is a considerable improvement in the grinding performance using graphite-impregnated grinding wheels over the performance obtained using conventional grinding wheels. The use of 0.5 wt% graphite provided better surface roughness and topography, lower grinding temperature, and decreased force; in addition, wheel consumption was lower, resulting in extended wheel life.

Grinding of Carbon/Epoxy Composites Using Electroplated CBN Wheel with Controlled Abrasive Clusters

2008 ◽  
Vol 389-390 ◽  
pp. 24-29 ◽  
Author(s):  
H.P. Yuan ◽  
Hang Gao ◽  
Yong Jie Bao ◽  
Yong Bo Wu
Keyword(s):  
Epoxy Composite ◽  
Epoxy Composites ◽  
Grinding Wheel ◽  
The Novel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Abrasive Grains ◽  
Dry Grinding ◽  
Conventional Grinding ◽  
Wheel Loading

Aiming at solving the problems of wheel loading in dry grinding of Carbon/Epoxy composite materials, a novel electroplated grinding wheel with controlled abrasive cluster was developed, in which the diameter of clusters is in Φ0.2 mm to Φ1.0 mm and the interspace between them is about 0.5 mm to 1.0 mm. A conventional electroplated grinding wheel with abrasive grains distributed randomly was fabricated in the same way. The comparison experiments involving C/E composite were conducted on a vertical spindle grinder with the novel and conventional grinding wheels. The results show that the grinding forces of novel wheel developed is more lower though little larger surface roughness, and the wheel loading phenomenon is markedly decreased compared with conventional electroplated wheel.

Characterization of High-Speed Alumina Abrasive Grinding Wheel

2020 ◽  
Vol 405 ◽  
pp. 365-369
Author(s):  
Zina Pavloušková ◽  
David Jech ◽  
Pavel Komarov ◽  
Ivana Ročňáková ◽  
Lucie Dyčková ◽  
...  
Keyword(s):  
High Speed ◽  
Raw Materials ◽  
Initial Mixture ◽  
Grit Size ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Abrasive Grains ◽  
Analysis Technique ◽  
High Speed Grinding

The high-speed grinding wheel can be defined as a self-sharpening composite structural tool composed from abrasive grains held in a specific binder. The main properties of grinding wheels depend on the type of abrasive elements, grit size, grade, binder and the resulting structure, which is influenced by several crucial technological processing steps. Preparation of an initial mixture of abrasive particles together with permanent binder’s mixture and temporary binder followed by pressing and high-temperature sintering is the essential technological step in the manufacturing of high-quality grinding wheels. High demands placed on functionality and quality together with constantly increasing effort to improve existing properties of grinding tools require detailed characterization of all input raw materials. For further research and development is crucial know, how each technological step can influence the final quality of the product. This contribution is focused on the characterization of four alumina abrasives with different grit size and two in chemical composition different binder mixtures which were used for the production of two different high-speed grinding wheels. Initial abrasive grains, binders and metallographic samples of high-speed grinding wheels were evaluated by means of scanning electron microscopy. The porosity of grinding wheels with different binding agents was also determined ustilizing digital image analysis technique.

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