scholarly journals Experimental Investigation of Wearing Grinding Wheels After Machining Sintered Carbide

Author(s):  
Jozef Peterka ◽  
Jakub Hrbál ◽  
Ivan Buranský ◽  
Jozef Martinovič

Abstract Solid cutting tools are widely applied in the machining of shape parts and mainly fabricated using the grinding operations. Solid cutting tools are of specific geometry and shape. The tool geometry is created by mutual movement grinding wheels and stock. In the grinding of its manufacturing, grinding wheels are worn out gradually with the grinding number increasing. The wearing grinding wheel has a significant influence on the accuracy geometry of the tool produced. The paper focuses on the wear of the grinding wheels based on diamonds, and the grinding wheels based on cubic boron nitride. The wear rate of the grinding wheels is affected by the properties of a grinding wheel, grinding conditions, and type of cutting material. A measure of the ability of a grinding wheel to remove material is given by the Grinding ratio. The grinding ratio (G ratio) is defined as the volume of material removed (Vw) divided by the volume of wheel wear (Vs). Periphery grinding wheels were used in the experiments. Cylindrical face grinding was used for the machining of sintered carbide stock with a diameter of 20 mm. The results of the experiment show that the diamond-based grinding wheels are more suitable for grinding sintered carbide.

1959 ◽  
Vol 81 (3) ◽  
pp. 187-199 ◽  
Author(s):  
E. J. Krabacher

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.


1996 ◽  
Vol 118 (3) ◽  
pp. 620-625
Author(s):  
R. B. Mindek ◽  
T. D. Howes

Workpiece profile accuracy, wheel wear, and thermal damage were investigated for the grinding of slots and vertical faces on MAR-M-247, Inconel 713C, and M-2 tool steel using both alumina and cubic boron nitride (CBN) grinding wheels. It was found when grinding with alumina wheels that the wheel corner and first 2.5 mm of the grinding wheel sidewall account for all the grinding forces in the vertical, horizontal, and transverse directions, and therefore is responsible for all the significant grinding done on the sideface of the workpiece. Since previous work links wheel wear and workpiece thermal damage during grinding to grinding forces, this finding suggests that the area around the wheel corner is the critical region of importance in grinding these types of profiles in terms of wheel wear and the heat input to the workpiece. These, in turn, are linked to workpiece profile accuracy and metallurgical damage. Results also show that striation marks inherent in sidewall grinding can be minimized by controlling the maximum normal infeed rate of the wheel. A method for minimizing the heat input into the workpiece by minimizing grinding force during vertical face grinding is also reported.


2021 ◽  
pp. 67-70
Author(s):  

The effect of a solid lubricant on the wear of cubic boron nitride grinding wheels on a ceramic bond of different hardness and grain size in the processing of high-speed steel is investigated. The dependences of the change in the wear of cubic boron nitride on the parameters of the processing mode are determined. An automated calculation system is proposed to control the consumption of cubic boron nitride grinding wheels in production conditions. Keywords: solid lubricant, grinding, high speed steel, cubic boron nitride grinding wheel, consumption, wear, grinding mode. [email protected]


2016 ◽  
Vol 874 ◽  
pp. 64-69
Author(s):  
Xun Chen

Grinding performance can be influenced by various grinding conditions including workpiece materials properties, grinding wheel properties, grinding operational parameters and dressing operational parameters. In order to achieve stable optimal grinding performance, it is important to select the most suitable operational control parameters to match grinding requirement and to minimize the effects of grinding wheel wear and other changes in the process environment. The paper presents a simple adaptive control logic strategy for the selection of dressing and grinding conditions based on available sensing techniques. In this study, desirable grinding behaviour is discussed to demonstrate how to extract useful process information to guide process parameter adjustment for a stable satisfactory grinding performance.


2020 ◽  
Vol 4 (4) ◽  
pp. 114
Author(s):  
Akira Mizobuchi ◽  
Atsuyoshi Tashima

This study addresses the wet grinding of large stainless steel sheets, because it is difficult to subject them to dry grinding. Because stainless steel has a low thermal conductivity and a high coefficient of thermal expansion, it easily causes grinding burn and thermal deformation while dry grinding on the wheel without applying a cooling effect. Therefore, wet grinding is a better alternative. In this study, we made several types of grinding wheels, performed the wet grinding of stainless steel sheets, and identified the wheels most suitable for the process. As such, this study developed a special accessory that could be attached to a wet grinding workpiece. The attachment can maintain constant pressure, rotational speed, and supply grinding fluid during work. A set of experiments was conducted to see how some grinding wheels subjected to some grinding conditions affected the surface roughness of a workpiece made of a stainless steel sheet (SUS 304, according to Japanese Industrial Standards: JIS). It was found that the roughness of the sheet could be minimized when a polyvinyl alcohol (PVA) grinding wheel was used as the grinding wheel and tap water was used as the grinding fluid at an attachment pressure of 0.2 MPa and a rotational speed of 150 rpm. It was shown that a surface roughness of up to 0.3 μm in terms of the arithmetic average height could be achieved if the above conditions were satisfied during wet grinding. The final surface roughness was 0.03 μm after finish polishing by buffing. Since the wet grinding of steel has yet to be studied in detail, this article will serve as a valuable reference.


Author(s):  
Krzysztof Nadolny ◽  
Witold Habrat

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.


2013 ◽  
Vol 405-408 ◽  
pp. 3302-3306
Author(s):  
Ming Yi Tsai ◽  
Shi Xing Jian ◽  
J. H. Chiang

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.


Author(s):  
M N Morgan ◽  
W B Rowe ◽  
S C E Black ◽  
D R Allanson

The thermal properties of the grinding wheel are required for energy partitioning in grinding. This paper describes an investigation of the effective thermal properties of alumina and cubic boron nitride (CBN) grinding wheels. Results are presented for a novel sensor that was designed to measure the bulk thermal properties of grinding wheel samples. The effective bulk thermal properties of the grinding wheel and the effective thermal properties of the abrasive grains were also investigated. It was found that the bulk thermal property is dominated by the properties of the bond and does not account for the improved thermal performance of CBN compared with alumina. Values of the effective thermal conductivities for alumina and CBN abrasive grains are therefore proposed. It is concluded that the effective thermal conductivity of the grains is best obtained inversely from grinding experiments.


2011 ◽  
Vol 338 ◽  
pp. 701-705
Author(s):  
Xiao Jun Zhu ◽  
Wen Sheng Xia

The key technology of the cutter that cutting hardened steel was researched by high speed milling machining method. At first ,three cutting elements of high speed milling machining was narratived, and we can obtain the principle of selection of parameters of cutting velocity, feed per tooth, longitudinal cutting depth and cutting width of axial, etc. With HSM ,we discussed the performance and selection points of tool material of coated cemented carbide, ceramic, cubic boron nitride , synthetic diamond and so on, and obtained the effect of the main tool geometry for the cutting process in HSM. The second, it analysised type and reason of damage of high speed cutting tools, and introduced three detection methods of tools. Finally, it was summarized and concluded.


1994 ◽  
Vol 116 (2) ◽  
pp. 260-262 ◽  
Author(s):  
Z. M. Bzymek ◽  
G. Song ◽  
T. D. Howes ◽  
R. E. Garrett

In this paper, various Cubic Boron Nitride (CBN) grinding wheels designed to suppress chatter are statically and dynamically analyzed and compared by means of the Finite Element Method (FEM). As a result of these analyses, a flexible wheel with a variable thickness hub is proposed. Theoretically, the new wheel should suppress chatter and thus be a major step forward in grinding wheel design.


Sign in / Sign up

Export Citation Format

Share Document