Effect of Electrolytes on Quality Characteristics of Glass during ECDM

2015 ◽  
Vol 658 ◽  
pp. 141-145 ◽  
Author(s):  
Pankaj Kumar Gupta ◽  
Akshay Dvivedi ◽  
Pradeep Kumar

Electrochemical discharge machining (ECDM) is an ideal process for machining of nonconductive materials in micro-domain. The material removal takes place due to combined action of localised sparks and electrolysis in an electrolytic chamber. The electrolyte is most important process parameter for ECDM as it governs spark action as well as electrolysis. This article presents a comparison of three preferred electrolytes used in ECDM viz. NaCl, KOH and NaOH on drilling of glass workpiece material. The quality characteristics measured are material removal rate (MRR) and hole overcut. Results reveal that NaOH provides 9.7 and 3.8 times higher MRR than NaCl and KOH respectively. MRR and hole overcut are found significantly affected by spark characteristics.

2015 ◽  
Vol 220-221 ◽  
pp. 743-748
Author(s):  
Justyna Molenda ◽  
Adam Charchalis

The high demands required today by manufacturing engineers for machine parts and tools necessitate very precise machining. The finishing processes are an important perspective to be considered today for meeting the goals like parallelism, tolerances, flatness, and smooth surface. These processes are high-precision abrasive processes used to generate surfaces of desired characteristic such as geometry, form, tolerances, surface integrity, and roughness characteristics. A leading importance in this perspective has the lapping process. It leads to a surface with low roughness and high precision. The topographical structure resulting from lapping is very advantageous in sliding joints, because of the high ability of lubricant retention, as well as in nonsliding joints because of the high load-carrying ability. Many materials can be lapped, including glass, ceramic, plastic, metals and their alloys, sintered materials, satellite, ferrite, copper, cast iron, steel, etc.This paper reports the observations of steel C45 elements lapping process results. Workpieces were rollers with diameter 17 mm and height 10 mm placed in the conditioning rings with use of workholdings. Samples were divided to three groups according to their Vicker’s hardness: 160, 440, and 650 HV. After grinding, lapping process was conducted. Experiments were carried out with an angular speed of the lapping plate set at 65 RPM, and lapping velocity was v = 49 m/min. The lapping pressure was provided by dead weights and during experiments executing p = 0.04 MPa. Samples were lapped during 10, 15 and 20 minutes. Abrasive slurry was composed of silicon carbide grains mixed with kerosene and machine oil. Abrasive grains size was F400/17.The material removal rate (MRR) and specimens surface characteristic are studied in the light of workpiece material hardness. Test results show that applied process parameters are the best for steel which hardness is 440 HV. In that case, the lowest values of Raparameter were obtained in conjunction with satisfactory values of material removal rate. It can be also seen, as could be predicted, that lapping time influenced on lapping results. MRR increases and surface roughness decreases with time. The worst lapping results were obtained for normalized steel (160HV). It can be the effect of surface damage, like scratching and grooving by harder abrasive grains.


2011 ◽  
Vol 487 ◽  
pp. 238-242 ◽  
Author(s):  
Min Li ◽  
Qiu Sheng Yan ◽  
Jia Bin Lu ◽  
Jing Fu Chai

Method of compound machining is used to process single crystal silicon and SrTiO3 ceramic substrates, and the factors on effects of compound machining are studied such as magnetic field intensity, processing time, rotating speed of lapping plate and lapping pressure. The results show that the roughness of work pieces processed by compound machining are smaller than that by lapping based on cluster MR effect and polyurethane pad polishing process, while the material removal rate is higher than polyurethane pad polishing process, therefore, compound machining shows its synergistic effect between lapping based on cluster MR effect and polyurethane pad polishing process. The type and properties of workpiece material, and machining parameters both have a significant impact on the roughness and material removal rate of compound machining process of polyurethane polishing pad and cluster abrasive brush based on MR effect.


2021 ◽  
Vol 12 (1) ◽  
pp. 97-108
Author(s):  
Chaoqun Xu ◽  
Congfu Fang ◽  
Yuan Li ◽  
Chong Liu

Abstract. Lapping and polishing technology is an efficient processing method for wafer planarization processing. The structure of the fixed abrasive pad (FAP) is one of the most concerning issues in the research. The FAP structure affects the pressure distribution on the wafer surface, and the pressure distribution during processing has a significant influence on the wafer surface. Therefore, in this paper, a better pressure distribution is obtained by adjusting the angle of the spiral arrangement and the damping distribution of the damping layer of the FAP, thereby obtaining better processing quality. Based on the above theory, a new type of FAP, with coupling between the arrangement of the pellets and the damping regulation of the damping layer, was designed and optimized. The machining effects of different FAPs on the workpiece surface are compared in terms of material removal rate, material removal thickness, and surface roughness. The test results show that the workpiece material removal rate is higher than that of the traditional FAP when using the optimized FAP. The non-uniformity of the optimized FAP for that of material removal was 4.034 µm, which was lower than the traditional FAPs by 24.4 % and 17.6 %, respectively. The average surface roughness, Ra, of the optimized FAP is 0.21 µm, which is lower than 19.1 % and 12.5 % of the two traditional FAPs, respectively. Therefore, workpiece material removal and distribution are more uniform, and the surface quality of the workpiece is better when the optimized FAP processing is used. The test results prove that the optimized pellet arrangement and damping can achieve a better surface quality of the workpiece, which can meet the precision lapping process requirements for high-quality surfaces and large-scale production of brittle and hard materials such as sapphire.


2019 ◽  
Vol 52 (7-8) ◽  
pp. 1167-1176 ◽  
Author(s):  
Parvesh Antil ◽  
Sarbjit Singh ◽  
Sunpreet Singh ◽  
Chander Prakash ◽  
Catalin Iulian Pruncu

The advanced manufacturing and machining techniques are adopting a population-based metaheuristic algorithm for production, predicting and decision-making. Using the same approach, this paper deals with the application of bees algorithm and differential evolution to forecast the optimal parametric values aiming to obtain maximum material removal rate during electrochemical discharge machining of silicon carbide particle/glass fiber–reinforced polymer matrix composite. The bees algorithm follows swarm-based approach, while differential evolution works on a population-based approach. The experimental design was prepared on the basis of Taguchi’s methodology using an L16 orthogonal array. For the experimental analysis, the main variables in the process, that is, electrolyte concentration (g/L), inter-electrode gap (mm), duty factor and voltage (volts), were selected as main input parameters, and material removal rate (mg/min) was adjudged as output quality characteristic. A comparative investigation reveals that the maximum material removal rate was obtained by the parametric value proposed by differential evolution that follows the bees algorithm and Taguchi’s methodology. Furthermore, the results prove that the differential evolution algorithm has better collective assessment capability with a rapid converging rate.


Author(s):  
Baoyang Jiang ◽  
Shuhuai Lan ◽  
Jun Ni

Electrochemical discharge machining (ECDM) is a non-conventional micromachining technology, and is highlighted for non-conductive brittle materials. However, the outcomes of ECDM have many restrictions in application due to limitations on efficiency, accuracy, and machining quality. In this paper, a drilling incorporated ECDM process is presented and analyzed to enhance material removal rate in ECDM drilling process. Incorporating micro-drilling into ECDM significantly increases the rate of material removal, especially in deep hole drilling. As fundamentals of the machining process, material removal mechanisms have been investigated to account for the increment in material removal rate by incorporating micro-drilling. Vibration of tool electrode, induced by a piezo-actuator, was introduced to further enhance material removal rate. Quantitative studies were conducted to determine the appropriate process parameters of drilling incorporated ECDM with tool vibration.


2019 ◽  
Vol 4 (1) ◽  
pp. 230-237
Author(s):  
Luboslav Straka ◽  
Gabriel Dittrich

The volume stock removal from the workpiece during the EDM is one of the important parameters that characterize the productivity of the electro-erosion process itself. Therefore, in terms of the economic efficiency of the electro-erosion process, it is appropriate that the value of the MRR parameter is as high as possible. The paper describes the results of experimental research to identify the extent of influence of the physical properties of the workpiece material on the workpiece material removal rate at EDM. The experiments were carried out using an Aggregron Hyperspark 3 electro-erosion machine on selected tool steels. As a tool electrode material for experimental purposes, graphite with the designation EX-60 was chosen because of its practical advantages.


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