Optimizing the Grinding Process through Reduction of the Loading of Grinding Tool by Infiltration

2016 ◽  
Vol 1136 ◽  
pp. 71-77
Author(s):  
Bahman Azarhoushang ◽  
Rolf Rinderknecht ◽  
Alireza Vesali ◽  
Juergen Struss

The loading of the grinding wheel and adhesion of the workpiece material to the cutting edges of the grinding tool are among the main reasons which limit the process efficiency when grinding ductile materials. The micro topography of the grinding tool changes drastically as a result of loading. Higher grinding forces and temperatures, poorer surface quality and process accuracy are the consequences of the adhesion of the workpiece material to the grinding tool surface. A novel and promising technique to reduce the possibility of loading and adhesion in the grinding process is the infiltrating of the grinding tool. This study describes the results of infiltration of vitrified bonded conventional grinding wheels with graphite in the surface grinding process. The effects of infiltration have been studied for the first time on various grinding wheels with different grain materials, grit sizes, porosity and hardness. Two different types of steel which are very popular in the automobile industry, 100Cr6 and 16MnCr5, were chosen as the workpiece material by the surface grinding experiments. The selected cutting parameters cover a wide range of the practical surface grinding processes which are utilized generally in the industry. It has been experimentally shown that the type of infiltration plays an important role in reducing the loading of the wheel. Better surface quality and longer dressing intervals are the main results of the infiltration of the grinding tools.

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.


Author(s):  
Sebastian Barth ◽  
Michael Rom ◽  
Christian Wrobel ◽  
Fritz Klocke

The prediction of the grinding process result, such as the workpiece surface quality or the state of the edge zone depending on the used grinding wheel is still a great challenge for today's manufacturers and users of grinding tools. This is mainly caused by an inadequate predictability of force and temperature affecting the process. The force and the temperature strongly depend on the topography of the grinding wheel, which comes into contact with the workpiece during the grinding process. The topography of a grinding wheel mainly depends on the structure of the grinding wheel, which is determined by the recipe-dependent volumetric composition of the tool. So, the structure of a grinding tool determines its application behavior strongly. As result, the knowledge-based prediction of the grinding wheel topography and its influence on the machining behavior will only be possible if the recipe-dependent grinding wheel structure is known. This paper presents an innovative approach for modeling the grinding wheel structure and the resultant grinding wheel topography. The overall objective of the underlying research work was to create a mathematical-generic grinding tool model in which the spatial arrangement of the components, grains, bond, and pores, is simulated in a realistic manner starting from the recipe-dependent volumetric composition of a grinding wheel. This model enables the user to determine the resulting grinding wheel structure and the grinding wheel topography of vitrified and synthetic resin-bonded cubic boron nitride (CBN) grinding wheels depending on their specification and thus to predict their application behavior. The originality of the present research results is a generic approach for the modeling of grinding tools, which takes into account the entire grinding wheel structure to build up the topography. Therefore, original mathematical methods are used. The components of grinding wheels are analyzed, and distribution functions of the component's positions in the tools are determined. Thus, the statistical character of the grinding wheel structure is taken into account in the developed model. In future, the presented model opens new perspectives in order to optimize and to increase the productivity of grinding processes.


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.


Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali

The efficiency of the grinding process highly depends on the coolant lubricant used. In grinding with CBN grinding wheels grinding oils are used increasingly. In the last decade new grinding oils based on different oil types are brought into the market, whose effect on the CBN grinding wheels performance until now not sufficiently been investigated. The Institute of Grinding and Precision Technology (KSF) investigated the influence of four different grinding oils on the performance of vitrified CBN grinding while grinding of 100Cr6 (M.-No. 1.3505), which is a heat-treatable steel with a very good grindability, and Nimonic A80, which is a difficult to grind heat-resistance superalloy. The obtained results show that the performance of the vitrified CBN grinding wheels—while using grinding oil as coolant lubricant—regarding the quality of the work piece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the viscosity of the grinding oil. Moreover, the results show that the surface quality and the grinding forces while using different grinding oils depend significantly on the work piece material.


2021 ◽  
Author(s):  
Maikel Strug ◽  
Berend Denkena ◽  
Bernd Breidenstein ◽  
Alexander Krödel-Worbes

Abstract Non-productive auxiliary processes affect the single part and small badge production of milling tools. The key production process grinding is inevitably linked to the auxiliary conditioning process. The time demand of those process steps decreases the overall productivity of the manufacturing process. However, today the machine operator decides on conditioning cycles individually by the use of experience. Until today, there is no objective data based approach available that supports the initiation of these conditioning processes or the adaption of the grinding process itself in order to improve its process efficiency. For this purpose, a process related topography evaluation method of the grinding wheel surface is developed within this study. For the measurement an optical method based on laser triangulation is used. The measurement system is implemented into a common tool grinding machine tool. In addition, characteristic topography values are defined that show the wear conditions of the grinding tool. Moreover, the data is summarized in a database of wear conditions. The developed measurement method can save grinding and dressing tool resources, process times and minimizes scrap parts. In addition, an adaptation of the process and a targeted launch of auxiliary processes can be enabled. The novel characteristic-based topography measurement creates the opportunity to enhance the tool life of the grinding wheels up to 30 % without losing productivity.


10.14311/1598 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Ondrej Jusko

This paper focuses on the influence of various types of abrasive grains on cutting properties during the grinding process for bearing steel. In this experiment, not only conventional super-hard abrasive materials but also a new type of abrasive material were employed in grinding wheels. The measurement results were compared, and an evaluation was made of the cutting properties of the new abrasive material. The options were then evaluated for their practical applicability. The measurement results indicated that a grinding wheel with Abral and SG grains is the most suitable for grinding hardened bearing steel in order to achieve the best roughness and geometrical accuracy.


2011 ◽  
Vol 325 ◽  
pp. 147-152
Author(s):  
Qiu Lin Niu ◽  
Guo Giang Guo ◽  
Xiao Jiang Cai ◽  
Zhi Qiang Liu ◽  
Ming Chen

As two kinds of advanced titanium alloys, TC18 and TA19 were introduced in this paper. The machinabilities of TC18 and TA19 alloys were described in the grinding process. Grinding experiments were completed using green silicon carbide grinding wheel with the coarser 100 grit. Grinding forces and specific energy in surface grinding were investigated. And then, for studying the grinding characteristic, SEM images of the workpiece material were obtained. The results indicated that specific chip formation had the great effect on the mechanism of grinding TC18 and TA19 alloys, and the scratch was the main characteristic of surface grinding. TC18 alloy had the poor grinding performance compared to TA19 alloy.


Author(s):  
Krzysztof Nadolny ◽  
Witold Habrat

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.


2014 ◽  
Vol 1017 ◽  
pp. 237-242
Author(s):  
Heike Kitzig ◽  
Nima Jandaghi ◽  
Bahman Azarhoushang ◽  
Alireza Vesali

In order to decrease the negative environmental impacts of the cutting fluids (for example, disposal of grinding sludge) and also to reduce the manufacturing costs and the required space for the machines the dry grinding can be a conceivable alternative for the conventional grinding processes. Nevertheless, dry grinding has not been widely introduced into industry because of the high temperature generated in the grinding zone and difficulties of heat transfer without coolants. Selection of the proper grinding wheel bonds, grit sizes and concentration has significant effect on the grinding performance and the generated heat in the contact zone. This paper addresses the effects of the grinding wheel bond and the concentration on the dry grinding process efficiency through comparing the results of the carried out experiments with three resin bonded cBN-cup-wheels, each consisting different bond components. For this purpose, surface roughness and thermal damages during dry and wet grinding (utilizing grinding oil) by three different resin bonds were measured. The results show almost identical surface roughness values for dry and wet grinding. Furthermore, using the resin-kryolith-graphite bonded wheel leads to a reduction in thermal damages on the workpiece. Through different experiments, it was shown that the different bonds, used in this study, have significant influence on the chip loading of the grinding wheels. This is contributed to the different chip formation mechanisms and induced grinding temperatures when grinding by the different wheel bonds.


Author(s):  
Radu Pavel ◽  
Anil Srivastava

The grinding process involves more variables than most of the other machining processes. In the past, grinding process has been viewed as an art more than an exact science. This paper presents a monitoring and model generation strategy developed to allow science-based optimization and control of the grinding process. The monitoring solution involves simultaneous acquisition of power, forces, acoustic emission and vibration data generated during surface grinding. A custom build data acquisition program helps capture the information and visualize the process condition. Dressing consistency and spindle condition are monitored through the same system. Part of the data is processed off-line to determine coefficient values for generalized equations that model main monitored parameters. An optimization relative to cycle time or cost can be conducted based on the results gathered for each combination of grinding wheel, workpiece material and metalworking fluid. The procedure requires a minimal number of experimental runs to determine the model coefficients. The solution opens the path towards the development of a model-based condition monitoring system with adaptive control.


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