scholarly journals Electrochemical and X-ray Examinations of Erosion Products during Dressing of Superhard Grinding Wheels Using Alternating Current and Ecological Electrolytes of Low Concentration of Chemical Compounds

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1375
Author(s):  
Marcin Gołąbczak ◽  
Andrzej Gołąbczak ◽  
Barbara Tomczyk

This article introduces significant cognitive and usable values in the field of abrasive technology especially in the development of new methods of the electrochemical dressing of superhard grinding wheels with metal bonds. Cognitive values mainly concern the elaboration of the theoretical backgrounds of the electrochemical digestion of compounds of grinding wheel metal bond and gumming up products of the cutting surface of grinding wheel (CSGW). Cognitive values also deal with determining the mathematical relationships describing the influence of technological conditions of dressing on shaping of cutting abilities of superhard grinding wheels. On the other hand, the useful values refer to the industry implementation of the elaborated method and equipment for the electrochemical dressing of suparhard grinding wheels using alternating current (ECDGW-AC). The cost of the device for the realization of this process is low and can be applied in the production conditions. The novel achievements presented in the article are: the elaboration of a new method and equipment for electrochemical dressing of superhard grinding wheels (ECDGW-AC), the selection of electrolytes of low concentration of chemical compounds, tests concerning the digestion of grinding wheel metal bond compounds and gumming up products of CSGW using X-ray analysis, as well as the determination of chemical reactions taking place during elaborated new dressing process, the elaboration of mathematical relationships describing influence of technological conditions of this process on dressing speed and shaping of cutting abilities of superhard grinding wheels, and the performance of technological tests of dressing of superhard grinding wheels using ECDGW-AC method. The elaborated method can be used in ambient temperature and does not cause thermal damages of abrasive grains of cutting surface of grinding wheel and is useful not only for dressing super hard grinding wheels but also for correcting their geometrical deviations.

Author(s):  
A Gołabczak ◽  
J Kozak

In this paper the development of an effective hybrid electrodischarge and electrochemical profiling/dressing system is depicted. To realize the profiling of superhard grinding wheels, an innovative segmental tool electrode has been designed and tested. The principle of operating this system, the case for its realization, mathematical modelling, and experimental results concerning dressing of grinding wheels is discussed. The results of the investigation demonstrate the usefulness of a hybrid system for the profiling of superhard grinding wheels and the shaping macro- and micro-geometry of the cutting surface grinding wheel (CSGW).


2014 ◽  
Vol 1017 ◽  
pp. 249-254
Author(s):  
Qiu Lian Dai ◽  
Fang Yi You ◽  
Can Bin Luo

The possibility of using the new processing technique of vacuum evaporative pattern casting (V-EPC) process to fabricate the Al-Si based bonded diamond grinding wheels was explored in this paper. Distribution of diamond grits in the diamond/EPS composite pattern and in the grinding layer of the cast of the grinding wheel were analyzed. Microstructures and mechanical properties of the metal bonds and diamond composites fabricated by V-EPC process were studied. It is confirmed that thermal damage of the diamond grits did not occur. Strong bonding between metal bond and diamond grits can be produced. However, the uniformity of the distribution of diamond grits in the metal matrix should be further improved. Also, further hardening on the metal bond is necessity by trying other kinds of aluminum alloys.


Mechanik ◽  
2015 ◽  
pp. 711/117-711/121
Author(s):  
Andrzej Gołąbczak ◽  
Marcin Gołąbczak ◽  
Robert Święcik ◽  
Marcin Galant ◽  
Dariusz Kaczmarek

Author(s):  
M. J. Jackson

Grinding wheel wear is a significant problem when the wheel has to be continuously dressed in order to maintain high productivity and high quality ground surfaces, especially during the manufacture of camshafts and crankshafts for automotive applications. This paper describes the use of x-rays to specifically engineer bonding systems for conventional abrasive grinding wheels so the wheel wears less during continuous dressing operations. The paper explains how the use of x-rays can be used to develop the next generation of bonding systems that will allow the grinding wheel to be cleaned and dressed with a laser without damaging the structure of the grinding wheel.


2012 ◽  
Vol 23 (5) ◽  
pp. 539-546 ◽  
Author(s):  
Carlos Estrela ◽  
Manoel Damião Sousa-Neto ◽  
Orlando Aguirre Guedes ◽  
Ana Helena Gonçalves Alencar ◽  
Marco Antonio Hungaro Duarte ◽  
...  

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.


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.


2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.


2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Xining Zhang ◽  
Xu Liu ◽  
Huan Zhao

Grinding is a vital method in machining techniques and an effective way to process materials such as hardened steels and silicon wafers. However, as the running time increases, the unbalance of grinding wheels produce a severe vibration and noise of grinding machines because of the uneven shedding of abrasive particles and the uneven adsorption of coolant, which has a severe and direct impact on the accuracy and quality of parts. Online balancing is an important and necessary technique to reduce the unbalance causing by these factors and adjust the time-varying balance condition of the grinding wheel. A new active online balancing method using liquid injection and free dripping is proposed in this paper. The proposed online balancing method possesses a continuous balancing ability and the problem of losing balancing ability for the active online balancing method using liquid injection is solved effectively because some chambers are full of liquid. The residual liquid contained in the balancing chambers is utilized as a compensation mass for reducing rotor unbalance, where the rotor phase is proposed herein as a target for determining the machine unbalance. A new balancing device with a controllable injection and free dripping structure is successfully designed. The relationship between the mass of liquid in the balancing chamber and the centrifugal force produced by liquid is identified. The performance of the proposed method is verified by the balancing experiments and the results of these experiments show that the vibration of unbalance response is reduced by 87.3% at 2700 r/min.


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