Slot and Vertical Face Grinding of Aerospace Components

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.

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.


1971 ◽  
Vol 93 (4) ◽  
pp. 1129-1133 ◽  
Author(s):  
S. Malkin ◽  
N. H. Cook

The nature and extent of grinding wheel wear in precision grinding were investigated directly from the wear particles removed from the wheel. A statistical analysis of the wear particle size distributions was developed to determine the relative amounts of bond fracture, grain fracture, and attritious wear. Most of the wear consists of grain and bond fracture particles with relatively more bond fracture occurring with softer wheels. The rate at which fracture wear occurs is directly related to the grinding forces and the amount of binder in the wheel. The attritious wear, although contributing insignificantly to the total, is the most important form of wear as it is directly related to the size of the wear flats, grinding forces, and workpiece burn, and therefore controls grain and bond fracture wear.


2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.


2016 ◽  
Vol 1136 ◽  
pp. 60-65
Author(s):  
Bin Jiang ◽  
Yu Can Fu ◽  
Zheng Cai Zhao ◽  
Bo Ping ◽  
Hai Ning Wang ◽  
...  

Electroplated profiled superabrasive grinding wheels which integrate both advantages of grinding and profile milling have been widely used in the machining process the wide chord hollow fan blade rabbets made of Ti-6Al-4V alloy. However, the employment of these tools has been impeded by drastic forces and thermal damage. In order to investigate the variation regularities of grinding forces and temperature with different machining parameters, experiments were carried out with single layer electroplated CBN grinding wheels. Grinding forces and temperature were measured and analyzed. Meanwhile, tool life and metallography of workpiece were studied. The results showed that higher spindle speed leads to lower forces and higher temperature. With the increase of feed rate and radial cutting depth, forces and temperature increase. Strong adherence of chips makes abrasives grits blunt which results in the increase of grinding forces after a great deal of tests. Metallographic structure of the machined workpiece is almost identical with the original sample.


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]


2009 ◽  
Vol 76-78 ◽  
pp. 163-168 ◽  
Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali

The efficiency of using of CBN grinding wheels highly depends on the dressing process as well as on the coolant lubricant used. The Institute of Grinding and Precision Technology (KSF) investigated the performance of vitrified CBN grinding wheels -being dressed using different parameters- while using two different grinding oils and two different water-miscible coolant lubricants. The obtained results show that the performance of the vitrified CBN grinding wheels regarding the quality of the workpiece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the dressing conditions and the type of the coolant lubricant used. Compared to the water-miscible coolant lubricants, the grinding oils show better results.


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.


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.


2005 ◽  
Vol 291-292 ◽  
pp. 213-220 ◽  
Author(s):  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
Hitoshi Ohmori ◽  
...  

In V-groove ELID grinding process, to achieve optimal grinding performance and satisfactory surface quality and profile accuracy, metal bonded diamond grinding wheels need to be carefully sharpened. In this paper, we applied the proposed new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing to sharpen the edge of large grinding wheels. The minimum wheel tip radiuses of 6.3 and 8.5µm were achieved for the #4000 and #20000 grinding wheels. The truing mechanisms and sharpening performance are also discussed.


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.


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