Ductile-Regime Grinding: A New Technology for Machining Brittle Materials

1991 ◽  
Vol 113 (2) ◽  
pp. 184-189 ◽  
Author(s):  
T. G. Bifano ◽  
T. A. Dow ◽  
R. O. Scattergood
Keyword(s):  
Material Removal ◽  
New Technology ◽  
Brittle Materials ◽  
Ductile Material ◽  
Grinding Wheel ◽  
Precision Engineering ◽  
Workpiece Material ◽  
Surface Finishes ◽  
Wheel Revolution ◽  
Complex Shapes

Because of recent advances in precision engineering that allow controlled grinding infeed rates as small as several nanometers per grinding wheel revolution, it is possible to grind brittle materials so that the predominant material-removal mechanism is plastic-flow and not fracture. This process is known as ductile-regime grinding. When brittle materials are ground through a process of plastic deformation, surface finishes similar to those achieved in polishing or lapping are produced. Unlike polishing or lapping, however, grinding is a deterministic process, permitting finely controlled contour accuracy and complex shapes. In this paper, the development of a research apparatus capable of ductile-regime grinding is described. Furthermore, an analytical and experimental investigation of the infeed rates necessary for ductile-regime grinding of brittle materials is presented. Finally, a model is proposed, relating the grinding infeed rate necessary for ductile material-removal with the properties of the brittle workpiece material.

Probabilistic model of surface layer removal when grinding brittle non-metallic materials

2021 ◽  
Vol 23 (2) ◽  
pp. 6-16
Author(s):  
Sergey Bratan ◽  
◽  
Stanislav Roshchupkin ◽  
Alexander Kharchenko ◽  
Anastasia Chasovitina ◽  
...  
Keyword(s):  
Surface Layer ◽  
Contact Zone ◽  
Probabilistic Model ◽  
Material Removal ◽  
Brittle Materials ◽  
Grinding Wheel ◽  
Metallic Materials ◽  
Deformable Solid ◽  
Metallic Material ◽  
Wide Range

Introduction. The final quality of products is formed during finishing operations, which include the grinding process. It is known that when grinding brittle materials, the cost of grinding work increases significantly. It is possible to reduce the scatter of product quality indicators when grinding brittle materials, as well as to increase the reliability and efficiency of the operation, by choosing the optimal parameters of the technological system based on dynamic models of the process. However, to describe the regularities of the removal of particles of a brittle non-metallic material and the wear of the surface of the grinding wheel in the contact zone, the known models do not allow taking into account the peculiarities of the process in which micro-cutting and brittle chipping of the material are combined. Purpose of the work: to create a new probabilistic model for removing the surface layer when grinding brittle non-metallic materials. The task is to study the laws governing the removal of particles of brittle non-metallic material in the contact zone. In this work, the removal of material in the contact zone as a result of microcutting and brittle chipping is considered as a random event. The research methods are mathematical and physical simulation using the basic provisions of the theory of probability, the laws of distribution of random variables, as well as the theory of cutting and the theory of a deformable solid. Results and discussion. The developed mathematical models make it possible to trace the effect on material removal of the overlap of single cuts on each other when grinding holes in ceramic materials. The proposed dependences show the regularity of stock removal within the arc of contact of the grinding wheel with the workpiece. The considered features of the change in the probability of material removal upon contact of the treated surface with an abrasive tool and the proposed analytical dependences are valid for a wide range of grinding modes, wheel characteristics and a number of other technological factors. The obtained expressions make it possible to find the amount of material removal also for schemes of end, flat and circular external grinding, for which it is necessary to know the amount of removal increment due to brittle fracture during the development of microcracks in the surface layer. One of the ways to determine the magnitude of this increment is to simulate the crack formation process using a computer. The presented results confirm the prospects of the developed approach to simulate the processes of mechanical processing of brittle non-metallic materials.

Identification of Brittle-Ductile Material Removal Characteristics in Ultrasonic Aided Lapping of Engineering Ceramics

2010 ◽  
Vol 126-128 ◽  
pp. 487-492 ◽  
Author(s):  
Feng Jiao ◽  
Chong Yang Zhao ◽  
Bo Zhao
Keyword(s):  
Material Removal ◽  
Online Monitoring ◽  
Ductile Material ◽  
Precision Engineering ◽  
Monitoring Technology ◽  
Engineering Ceramics ◽  
Online Identification ◽  
Ductile Regime Machining ◽  
Wavelet Package Analysis ◽  
Ae Signals

For the precision engineering ceramics parts, semi-ductile regime machining technologies are usually adopted to obtain the final surface. It is very important to research the brittle-ductile material removal characteristics and corresponding monitoring technology in ultrasonic aided lapping of engineering ceramics to obtain better surface quality. A series of lapping tests were carried out in the paper and the influence law of lapping parameters on the ductile percentage of ultrasonic lapped surface was achieved, which enables to off-line identify the material removal characteristics. Though the material removal characteristics can be online judged through monitoring the ratio of lapping component forces qualitatively, the monitoring effect is worse just because of lower response frequency of dynamometer and the relativity of lapping force. In this paper, a novel online monitoring technology of material removal characteristics is put forward based on AE technology. Through the wavelet package analysis of AE signals, the discrimination index and standard of material removal characteristics can be obtained. It is proved that this technology can realize online identification of the brittle-ductile material removal characteristics in ultrasonic aided lapping of engineering ceramics effectively.

Surface/Subsurface Damage of Yttria Partially Stabilized Zirconia in Grinding Using Monolayer Brazed Diamond Wheel

2010 ◽  
Vol 431-432 ◽  
pp. 326-329
Author(s):  
Shu Sheng Li ◽  
Jiu Hua Xu ◽  
Yu Can Fu ◽  
Hong Hua Su
Keyword(s):  
Material Removal ◽  
Chip Thickness ◽  
Diamond Wheel ◽  
Critical Value ◽  
Subsurface Damage ◽  
Ductile Material ◽  
Grinding Wheel ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Yttria Partially Stabilized Zirconia

A new brazed monolayer diamond grinding wheel is developed with the same continuous cutting edge distance on the wheel surface. Surface/subsurface damage of yttria partially stabilized zirconia (Y-PSZ) in grinding using monolayer brazed diamond wheel is analyzed. In this investigation, the influence of the maximum undeformed chip thickness (hm) on material removal mechanism is analyzed. The experiment results show that the ground surface is almost in ductile material removal mode when hm is below the critical value for Y-PSZ, otherwise it will be the combined removal modes of brittle and ductile when hm is above the critical value.

scholarly journals Emitter-Receiver Piezoelectric Transducers Applied in Monitoring Material Removal of Workpiece during Grinding Process

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 9 ◽  
Author(s):  
Felipe Alexandre ◽  
Paulo de Aguiar ◽  
Reinaldo Götz ◽  
Martin Aulestia Viera ◽  
Thiago Lopes ◽  
...  
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Material Removal ◽  
Digital Signal ◽  
Piezoelectric Transducers ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Workpiece Material ◽  
Grinding Machine ◽  
Finishing Processes

Grinding is one of the most commonly used finishing processes in the manufacture of precision components that also needs to be monitored. Monitoring of the workpiece surface quality is considered highly complex due to particularities of the cutting tool and material removal mechanism. In this context, the monitoring of the grinding process is very important for the metalworking industry and a topic of great interest for machining researchers. Many studies on grinding process monitoring have been developed and most of them focus on process automation. The objective of this work is to monitor the workpiece material removal during grinding by using piezoelectric transducers in the emitter and receiver modes along with digital signal-processing techniques. Tests were performed on a peripheral surface grinding machine equipped with an aluminum oxide grinding wheel. The SAE 4340 steel grade was used as workpiece material. The transducer signals were sampled at a sampling frequency of 2 MHz. The digital signal processing was performed through spectrum analysis and the application of techniques such as root mean square. The mass of the workpieces was measured by means of a digital scale prior to and after grinding tests. The number of grinding passes was varied in order to increase the material removal. The results show that the monitoring technique proposed in this work is sensitive to the material removal in the grinding process. The appropriate selection of frequency bands allows for the best diagnosis in relation to the events that occur during the grinding process.

scholarly journals Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Service Life ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

scholarly journals Simulation of the ductile machining mode of silicon

2021 ◽  
Author(s):  
Hagen Klippel ◽  
Stefan Süssmaier ◽  
Matthias Röthlin ◽  
Mohamadreza Afrasiabi ◽  
Uygar Pala ◽  
...  
Keyword(s):  
Brittle Material ◽  
Material Removal ◽  
Machining Process ◽  
Ductile Material ◽  
Diamond Wire ◽  
Ductile Machining ◽  
Mesh Free ◽  
Diamond Wire Sawing ◽  
Material Removal Mode ◽  
Brittle Material Removal

AbstractDiamond wire sawing has been developed to reduce the cutting loss when cutting silicon wafers from ingots. The surface of silicon solar cells must be flawless in order to achieve the highest possible efficiency. However, the surface is damaged during sawing. The extent of the damage depends primarily on the material removal mode. Under certain conditions, the generally brittle material can be machined in ductile mode, whereby considerably fewer cracks occur in the surface than with brittle material removal. In the presented paper, a numerical model is developed in order to support the optimisation of the machining process regarding the transition between ductile and brittle material removal. The simulations are performed with an GPU-accelerated in-house developed code using mesh-free methods which easily handle large deformations while classic methods like FEM would require intensive remeshing. The Johnson-Cook flow stress model is implemented and used to evaluate the applicability of a model for ductile material behaviour in the transition zone between ductile and brittle removal mode. The simulation results are compared with results obtained from single grain scratch experiments using a real, non-idealised grain geometry as present in the diamond wire sawing process.

Development of a New Plate Polishing Technique with an Instantaneous Tiny-Grinding Wheel Cluster Based on Magnetorheological Effect

2008 ◽  
Vol 53-54 ◽  
pp. 155-160 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Ai Jun Tang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Abrasive Particles ◽  
Magnetorheological Effect ◽  
Material Removal Model ◽  
Mr Effect ◽  
Removal Model

A new plate polishing technique with an instantaneous tiny-grinding wheel cluster based on the magnetorheological (MR) effect is presented in this paper, and some experiments were conducted to prove its effectiveness and applicability. Under certain experimental condition, the material removal rate was improved by a factor of 20.84% as compared with the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece was not obviously increased. Furthermore, the composite of the MR fluid was optimized to obtain the best polishing performance. On the basis of the experimental results, the material removal model of the new plate polishing technique was presented.

Parametric Study of Micro Machining Three Dimensional Microstructure with the Tiny-Grinding Wheel Based on the EMR Effect

2010 ◽  
Vol 447-448 ◽  
pp. 193-197
Author(s):  
Wei Qiang Gao ◽  
Qiu Sheng Yan ◽  
Yi Liu ◽  
Jia Bin Lu ◽  
Ling Ye Kong
Keyword(s):  
Magnetic Field ◽  
Material Removal Rate ◽  
Feed Rate ◽  
Material Removal ◽  
Rotation Speed ◽  
Optical Glass ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Machining Time ◽  
Fluctuation Phenomenon

Electro-magneto-rheological (EMR) fluids, which exhibit Newtonian behavior in the absence of a magnetic field, are abruptly transformed within milliseconds into a Bingham plastic under an applied magnetic field, called the EMR effect. Based on this effect, the particle-dispersed EMR fluid is used as a special instantaneous bond to cohere abrasive particles and magnetic particles together so as to form a dynamical, flexible tiny-grinding wheel to machine micro-groove on the surface of optical glass. Experiments were conducted to reveal the effects of process parameters, such as the feed rate of the horizontal worktable, feeding of the Z axis, machining time and machining gap, on material removal rate of glass. The results indicate that the feed rate of the worktable at horizontal direction has less effect on material removal rate, which shows a fluctuation phenomenon within a certain range. The feed rate of the Z axis directly influences the machining gap and leads to a remarkable change on material removal rate. Larger material removal rate can be obtained when the feeding frequency of Z direction is one time per processing. With the increase of rotation speed of the tool, material removal rate increases firstly and decreases afterwards, and it gets the maximum value with the rotation speed of 4800 rev/min. The machining time is directly proportional to material removal amount, but inversely proportional to material removal rate. Furthermore, material removal rate decreases with the increase of the machining gap between the tool and the workpiece. On the basis of above, the machining mode with the tiny-grinding wheel based on the EMR effect is presented.

Schleifen von WC-Co-Hartmetallen*/Grinding of Cemented Carbides (WC-Co)

2016 ◽  
Vol 106 (06) ◽  
pp. 374-379
Author(s):  
C. Wirtz ◽  
F. Vits ◽  
P. Mattfeld ◽  
F. Prof. Klocke
Keyword(s):  
Brittle Material ◽  
Brittle Materials ◽  
Material Behavior ◽  
Ductile Material ◽  
Cemented Carbides ◽  
Multi Phase

Beim Schleifen mehrphasiger Werkstoffe mit sprödhartem Charakter, beispielsweise Hartmetall, wurde ein Übergang von sprödhartem zu duktilem Werkstoffverhalten nachgewiesen. Der Fachartikel stellt eine neu entwickelte Methodik zur systematischen Analyse des Zerspanverhaltens – im Speziellen den Übergang von vorwiegend duktilem zu überwiegend sprödhartem Zerspanverhalten – für Hartmetalle vor.   In grinding of multi-phase, brittle materials, e. g. cemented carbides, a transition from predominantly brittle to predominantly ductile material behavior has been proven scientifically. This paper presents a newly developed methodology to analyze the material behavior of cemented carbides, in particular the transition from ductile to brittle material behavior.

scholarly journals The enhancement of cutting capacity of a grinding wheel when processing ductile steel blank parts by ultrasonic activation

2021 ◽  
pp. 55-62
Author(s):  
A. V. Khazov ◽  
◽  
A. N. Unyanin ◽  
Keyword(s):  
Numerical Simulation ◽  
Grinding Wheel ◽  
Ultrasonic Vibrations ◽  
Ultrasonic Activation ◽  
Workpiece Material ◽  
Steel Blank ◽  
Micro Cutting ◽  
Abrasive Grains ◽  
Junction Points ◽  
Cutting Capacity

The study aimed to identify the relations between the sticking intensity and ultrasonic vibrations (UV) used for processing and evaluate the wheels’ performance when grinding ductile materials blank parts. The authors carried out the numerical simulation of local temperatures and the 3H3M3F steel workpiece temperature when grinding by ultrasonic activation. The study determined that the application of ultrasonic vibrations with the amplitude of 3 µm causes the decrease in local temperatures by 13…40 %, and in blank part temperature – up to 20 %. The calculation identified that the activation of ultrasonic vibrations with the amplitude of 3 µm causes the decrease in the glazing coefficient by 33 % for cutting grain and by 7 % for deforming grain. When increasing the longitudinal feed rate or the grinding depth, the glazing coefficient increases to a lesser degree when using the ultrasonic vibration than in the case without ultrasonic activation. The authors carried out the numerical simulation of local temperatures when scratching the 3H3M3F steel specimens by single abrasive grains with ultrasonic activation. The sticking deformation and the stresses resulted from this deformation and affecting the junction points of sticking with grains with and without ultrasonic vibrations application are calculated. The experimental research included the micro-cutting of specimens with single abrasive grains. The experiments identified that the abrasive grains wear out and glaze to a lesser degree when micro-cutting a workpiece with ultrasonic vibrations activation. The lowering of the intensity of sticking of the workpiece material particles to the abrasive grains due to the adhesion causes the decrease in the glazing coefficient when using ultrasonic activation. The study considered the possibility to enhance the efficiency of flat grinding through the use of the energy of ultrasonic vibrations applied to a blank part in the direction with the grinding wheel axis. A workpiece fixed in the device between the vibration transducer and the support is one of the components of a vibration system. The authors performed the experiment when grinding 3H3M3F and 12H18N10T steel workpieces with the wheel face. When grinding with ultrasonic vibrations, the grinding coefficient increases up to 70 %, and the redress life increases twice or thrice.

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