Modeling of Material Removal Rate in Micro-ECG Process

Author(s):  
Kishore S. Gaikwad ◽  
Suhas S. Joshi

Microelectrochemical grinding (micro-ECG) is a variant of electrochemical grinding (ECG) process, in which material is removed by a combination of electrolytic dissolution and abrasive action that take place in a small interelectrode gap. This paper discusses analytical modeling of the material removal phenomenon in micro-ECG process to predict material removal rate. In the model, the phenomena, which contribute to the material removal in the process by electrolytic and abrasive actions, have been considered; these include streaming potential in the electrochemical action and shearing forces due to the flow of electrolyte through interelectrode gap and the abrasive action of grinding wheel. Two configurations of the process, viz., surface and cylindrical micro-ECG, have been modeled. The results have been validated by CFD simulation in the case of surface micro-ECG process, and specific experimentation in the case of cylindrical micro-ECG process.

2019 ◽  
Vol 8 (2) ◽  
pp. 3219-3222

Electrochemical grinding is combination of electrochemical machining and mechanical grinding process.in this process 90%-98% percentage of material are removed by electrochemical machining, only 3%-5% of materials can only remove by mechanical grinding process. Faradays law of electrolysis (or) reverse electroplating act as a basic principle for this ECG process. This ECG has various advantages than other machining process for high strength materials .low induvial stress, large depth of cut .here Monel 400 alloy take base material ,its Ni-Cu alloy so it’s have very high level corrosion resistance, so it’s used in marine engineering ,heat exchanger. Here silicon carbide abrasive insulated brass grinding wheel used instead of copper bonded diamond wheel. Voltage, electrolyte concentration, electrolyte flowrate take are the parameters of this process. Three factors and two levels of RSM methodology takes for optimization. The Analysis of variance (ANOVA) has been delivers the variation between the parameters performed to develop mathematical model. The parameters high voltage and concentration of electrolyte to produce maximum material removal rate.


2008 ◽  
Vol 53-54 ◽  
pp. 155-160 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Ai Jun Tang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao

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.


2010 ◽  
Vol 447-448 ◽  
pp. 193-197
Author(s):  
Wei Qiang Gao ◽  
Qiu Sheng Yan ◽  
Yi Liu ◽  
Jia Bin Lu ◽  
Ling Ye Kong

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.


2006 ◽  
Vol 304-305 ◽  
pp. 555-559 ◽  
Author(s):  
Chang He Li ◽  
Guang Qi Cai ◽  
Shi Chao Xiu ◽  
Q. Li

The material removal rate (MRR) model was investigated in abrasive jet precision finishing (AJPF) with wheel as restraint. When abrasive wore and workpiece surface micro-protrusion removed, the size ratio for characteristic particle size to minimum film thickness gradually diminishing, the abrasive machining from two-body lapping to three-body polishing transition in AJPF with grinding wheel as restraint. In the study, the material removal rate model was established according to machining mechanisms and machining modes from two-body to three-body process transition condition, and active number of particles in grinding zone were calculated and simulated. Experiments were performed in the plane grinder for material removal mechanism and academic models verification. It can be observed from experimental results that the surface morphology change dramatically to a grooved or micro-machined surface with all the grooves aligned in the sliding direction in two-body lapping mode. On the other hand, the surface is very different, consists of a random machining pits with very little sign of any directionality to the deformation in the three-body machining mode. Furthermore, the material removal rate model was found to give a good description of the experimental results.


2009 ◽  
Vol 416 ◽  
pp. 609-613
Author(s):  
Ming Li Zhao ◽  
Bo Zhao ◽  
Yu Qing Wang ◽  
Guo Fu Gao

Relative motion of single abrasive is analyzed for the different applied directions of longitudinal ultrasonic vibration, and its locus is simulated in the present paper. The research results show that the locus in two-dimensional ultrasonic vibration is only similar to that in y-direction, and both are close to sinusoid curves. The width of grooves scratched by abrasive grains y-direction (axial direction of grinding wheel) is two times of the vibration amplitude, and the material removal rate increases remarkably. In case of x-direction (tangential direction of grinding wheel) ultrasonic vibration, abrasive grains with periodic force impact material surface with high frequency vibration, which make material fracture removal easy. Therefore, the high efficiency essence of material removal in two-dimensional ultrasonic grinding is revealed in view of locus. In addition, according to the results of grinding experiments, under same conditions good surface quality can be obtained in two-dimensional ultrasonic grinding and material removal rate in common grinding is the lowest. Consequently it is further proved that the method of two-dimensional ultrasonic vibration grinding is an effective one for ceramic materials.


Author(s):  
Xinxiao Li ◽  
Patrick Chernjavsky ◽  
Katerina Angjeli ◽  
Sola Hoffman ◽  
Sara Frunzi ◽  
...  

Abstract Rotational atherectomy (RA) utilizes a high-speed, metal-bonded diamond-abrasive grinding wheel to remove the calcified atherosclerotic plaque inside arteries, restore blood flow, and treat cardiovascular diseases. RA operational guidelines have been clinically investigated to improve clinical outcomes and reduce complication rates, but are still in lack of consensus. Particularly, the effect of the grinding wheel rotational speed on plaque material removal rate (MRR) is unclear. This study experimentally investigates the RA MRR over a range of wheel rotational speeds based on a vascular simulator with a calcified plaque surrogate. The MRR, presented as the luminal area gain, with the increase of the number of grinding passes, was measured at the rotational speed of 120,000, 150,000, and 180,000 rpm. The luminal area was characterized via microscopy and image processing. The ground surface morphology and surface roughness at different rotational speeds were investigated. The results showed that a higher rotational speed led to a higher MRR and a smoother ground surface. This observation is significant for RA clinical guideline improvement.


2013 ◽  
Vol 797 ◽  
pp. 374-381
Author(s):  
Pei Lum Tso ◽  
Chao Chun Tseng

In order to cope with high demanded industry requirements. The super-hard alloys such as Tungsten Carbide have been widely used in aerospace and defense industries. So far, the grinding operation is still the most popular machining process being used to cut these materials in shape. But, owing to the nature of these materials mechanical properties, always made it very difficult to grind as well as to cut. Nevertheless, the allowable grinding parameters are resisted to very limited range and always require use very expensive super abrasive grinding wheel. Recently, study by many researchers show that the ultrasonic assist grinding had the advantage of higher material removal rate, less cutting force and lower cutting temperature. In the mean time, the tool life had been improved greatly. In this study, the conventional GC grinding wheel was used in the experiments to study the material removal rate; grinding force; surface roughness as well as specific grinding energy with and without the ultrasonic assist. The results show that these difficult-to-cut materials can be ground easier with proper ultrasonic assist and low-priced grinding wheel.


2009 ◽  
Vol 404 ◽  
pp. 1-10 ◽  
Author(s):  
Berend Denkena ◽  
Luis de Leon ◽  
B. Wang ◽  
Dennis Hahmann

Harder workpiece materials and increased efficiency requirements for grinding processes make the use of super abrasive grinding wheels indispensable. This paper presents newly developed processes for the dressing of super abrasive grinding wheels. The different bond systems of grinding wheels require distinct dressing process. In this paper, dressing processes for metal and vitrified bonded grinding wheels are investigated. It introduces the method of electro contact discharge dressing for the conditioning of metal-bonded, fine-grained multilayer grinding wheels. A description of the essential correlation between dressing parameters and the material removal rate of the bond material is presented. The considered parameters are the dressing voltage, the limitation of the dressing current and the feed as well as the infeed of the electrode. For the grinding of functional microgroove structures, multiroof profiles with microscopic tip geometries are dressed onto the grinding wheel. For this, a profile roller in combination with a special shifting strategy is applied on finegrained vitrified bonded grinding wheels.


2009 ◽  
Vol 76-78 ◽  
pp. 229-234 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Yong Yang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao

Experiments were conducted to polish optical glass with the magnetorheological (MR) effect-based tiny-grinding wheel cluster, and the influences of abrasive material, particle size and content on the material removal rate and surface roughness are investigated. The experimental results indicate that: the higher the hardness of abrasives, the higher the material removal rate, but the abrasives with lower hardness can obtain lower surface roughness. The better polishing quality of the workpiece can be obtained when the particle size of abrasives is similar to the particle size of magnetic particles. Moreover, the content of abrasives has an optimum value, and the material removal rate and the surface quality can not be improved further when the content of abrasives exceeds the optimum value. On the basis of above, the material removal model of the new planarization polishing technique is presented.


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