scholarly journals Integrating Operator Information for Manual Grinding and Characterization of Process Performance Based on Operator Profile

Author(s):  
Jayanti Das ◽  
Gregory L. Bales ◽  
Zhaodan Kong ◽  
Barbara Linke

Due to its high versatility and scalability, manual grinding is an important and widely used technology in production for rework, repair, deburring, and finishing of large or unique parts. To make the process more interactive and reliable, manual grinding needs to incorporate “skill-based design,” which models a person-based system and can go significantly beyond the considerations of traditional human factors and ergonomics to encompass both processing parameters (e.g., feed rate, tool path, applied forces, material removal rate (MRR)), and machined surface quality (e.g., surface roughness). This study quantitatively analyzes the characteristics of complex techniques involved in manual operations. A series of experiments have been conducted using subjects of different levels of skill, while analyzing their visual gaze, cutting force, tool path, and workpiece quality. Analysis of variance (ANOVA) and multivariate regression analysis were performed and showed that the unique behavior of the operator affects the process performance measures of specific energy consumption and MRR. In the future, these findings can be used to predict product quality and instruct new practitioners.

Author(s):  
Ramezan Ali Mahdavinejad ◽  
Mohsen Asghari Ilani

Electro Discharge Machining (EDM) known as an advanced machining process that much used for machining material with any hardness and complexity geometry in a high level of the accuracy in the cases of demand of the industrial application. The conception of the EDM process is included in applying electro-thermal energy in the gap, by discharge electrical power on the breaking point of the dielectric without any contact between electrodes. Due to the existing ability for removing debris from the surface, there is a lot of metallurgy defect on it. To improve and optimize EDM performance, the machine’s operating parameters, Input, during& output parameters, need to be optimized. Another handy way to reform of the view metallurgical must take picture sub-structure from the initial and subsequent layer. At the end for catching special status, adjust the technical parameters with metallurgical defects. Studies in case of the EDM have indicated that the appropriate selection of the way to control of the process, material, and operating parameters had considerably improved the process performance and also causing to was better the quality machined surface. This paper made a comprehensive review of the research studies in a different section of the EDM of various grades of titanium and its alloys. This review presents the simulation, experimental and theoretical studies on EDM that helped to improve the process performance, including material removal rate, surface quality, and tool wear rate, the stability of process among others. However, here are collected most of the research are done surrounding of EDM of Ti alloys as the developments of EDM and are seen material for future.


2010 ◽  
Vol 44-47 ◽  
pp. 1066-1069
Author(s):  
Li Li ◽  
Li Ling Qi ◽  
Zong Wei Niu

This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). Concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM are compared, machined surface characteristics are also compared between them. It is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.


Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar

This paper presents the experimental investigation on the electro-discharge machining of aluminum alloy 6061 reinforced with SiC particles using sintered Cu–W electrode. Experiments have been designed as per central composite rotatable design, using response surface methodology. Machining characteristics such as material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR) have been investigated under the influence of four electrical process parameters; namely peak current, pulse on time, pulse off time, and gap voltage. The process parameters have been optimized to obtain optimal combination of MRR, EWR, and SR. Further, the influence of sintered Cu–W electrode on surface characteristics has been analyzed with scanning electron microscopy, energy dispersive spectroscopy, and Vicker microhardness tests. The results revealed that all the process parameters significantly affect MRR, EWR, and SR. The machined surface properties are modified as a result of material transfer from the electrode. The recast layer thickness is increased at higher setting of electrical parameters. The hardness across the machined surface is also increased by the use of sintered Cu–W electrode.


2021 ◽  
Vol 1047 ◽  
pp. 62-67
Author(s):  
Shen Wang ◽  
Le Tong ◽  
Guang Jun Chen ◽  
Mao Xun Wang ◽  
Bin Dai ◽  
...  

7075 aluminum alloy is widely used due to its great performance, especially in aerospace area. In this paper, ultrasonic-assisted grinding technology is used to process 7075 aluminum alloy. The data is obtained through experiments, and the surface roughness and morphology of ultrasonic assisted grinding and conventional grinding under different spindle speeds, feed rates, and amplitudes are analyzed. Research has found that the increase in spindle speed and amplitude will improve the quality of the machined surface and reduce the surface roughness by 82.1% and 36%. However, with the increase of feed rate, the surface quality decreased significantly, and the surface roughness increased by 55.6%. The surface micro-morphology of the machined workpiece is observed, and the effects of different processing parameters on the surface micro-morphology are obtained.


Author(s):  
Igor Kiselev ◽  
Sergey Voronov ◽  
Sergey Arshinov

The examples of multi-variant simulation of 5-axis milling dynamics while the machining of 3-D shaped detail in the paper are presented. The simulation model takes into account tool and detail vibrations. The regeneration mechanism is embedded into the model. The diagram of tool speed influence on the vibration amplitudes and cutting forces magnitudes for the different area of the tool path are determined. The system dynamic parameters and the vibrations behavior and their effect on the machined surface shape for favourable and unwanted regimes are analyzed. The effect of the dynamic characteristics alteration of the workpiece while stock removal on the process behavior is considered. Some recommendations for the efficient cutting conditions setting on the base of the model application and the obtained results in the conclusion are discussed.


2011 ◽  
Vol 223 ◽  
pp. 691-700 ◽  
Author(s):  
Xavier Beudaert ◽  
Pierre Yves Pechard ◽  
Christophe Tournier

In the context of 5-axis flank milling, the machining of non-developable ruled surfaces may lead to complex tool paths to minimize undercut and overcut. The curvature characteristics of these tool paths generate slowdowns affecting the machining time and the quality of the machined surface. The tool path has to be as smooth as possible while respecting the maximum allowed tolerance. In this paper, an iterative approach is proposed to smooth an initial tool path. An indicator of the maximum feedrate is computed using the kinematical constraints of the considered machine tool, especially the maximum velocity, acceleration and jerk. Then, joint coordinates of the tool path are locally smoothed in order to raise the effective feedrate in the area of interest. Machining simulation based on a N-buffer algorithm is used to control undercut and overcut. This method has been tested in flank milling of an impeller and can be applied in 3 to 5-axis machining.


2014 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Raju S. Pawade

The paper presents the surface integrity analysis in ball end milling of thin shaped cantilever plate of Inconel 718. It is noticed that the workpiece deflection has significantly contributed to machined surface integrity in terms of surface topography and subsurface microhardness. The ball end milling performed with 15° workpiece inclination with horizontal tool path produced higher surface integrity which varies with the location of machined surface region. In general, the mid portion of the machined plate shows lower surface roughness and microhardness with less surface defects.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6074
Author(s):  
Tingting Ni ◽  
Qingyu Liu ◽  
Zhiheng Chen ◽  
Dongsheng Jiang ◽  
Shufeng Sun

Micro electrical discharge machining (micro EDM) is able to remove conductive material by non-contact instantaneous high temperature, which is more suitable for machining titanium and its alloys compared with traditional machining methods. To further improve the machining efficiency and machined surface quality of micro EDM, the nano particle surfactant mixed micro EDM method is put forward in this paper. Experiments were conducted to explore the effect of nano particle surfactant on the micro EDM performance of titanium alloy. The results show that the material removal rate of micro EDM in dielectric mixed with TiO2 is the highest when open-circuit voltage is 100 V, followed by Al2O3 and ZrO2. Lower tool wear rate can be produced by using dielectric mixed with nano particle surfactant. The taper ratio of micro EDM in dielectric mixed with nano particle surfactant is higher than that in deionized water. The surface roughness Ra of micro EDM in dielectric mixed with TiO2 can be 50% lower than that in deionized water. It is helpful to improve the machining performance by adding surface surfactant in the dielectric of micro EDM.


2010 ◽  
Vol 154-155 ◽  
pp. 794-805 ◽  
Author(s):  
Yao Jang Lin ◽  
Yan Cherng Lin ◽  
A Cheng Wang ◽  
Der An Wang ◽  
Han Ming Chow

This study investigates the feasibility of EDM for processing ZrO2 and Al2O3 of non-conductive ceramics, which were covered by an assisted conductive material, an adherent copper foil, on the workpiece surface. The conductive material adhered on the surface of the non-conductive ceramics would induce a series of electrical discharges between the tool electrode and the workpiece in the initial stage of the EDM process. Thus, the pyrolytic carbon that cracked from kerosene was formed and deposited on the machined surface to maintain the progress of EDM. In this work, the essential EDM machining parameters were varied to determine the effects on material removal rate (MRR), electrode wear rate (EWR), and surface roughness. The stability of EDM progress and the surface integrities of ZrO2 and Al2O3 machined by EDM were also investigated. The aim of this study is to explore the feasibility and development of an applicable process for processing non-conductive ceramics through EDM. Moreover, the exploitation of this work can be applied to industrial applications and used to develop machining techniques for non-conductive ceramics.


Author(s):  
VG Ladeesh ◽  
R Manu

The electrically non-conductive materials like glass, ceramics, quartz, etc. are of great interest for many applications in modern industries. Machining them with high quality and at a faster rate is a challenging task. In this study, a novel technique called grinding aided electrochemical discharge drilling (G-ECDD) is demonstrated which uses a hollow diamond core drill as the tool for performing electrochemical discharge machining of borosilicate glass. The new hybrid technique enhances the material removal rate and machining accuracy to several folds by combining the thermal melting action of discharges and grinding action of the abrasive tool. This paper presents the experimental investigation on the material removal rate during G-ECDD of glass while using different electrolytes. An attempt has been made to explore the influence of electrolyte temperature on G-ECDD performance by maintaining the electrolyte at different temperatures. Experiments were conducted using three different electrolytes which include NaOH, KOH, and the mixture of both. The results obtained from this study revealed that an increase in temperature will favor chemical etching as well as electrochemical reaction rate. Also, it was observed that heating the electrolyte leads to an increase in the bubble density and enhances the ion mobility. This causes the formation of gas film at a faster rate and thereby improving the discharge activity. Thus, machining will be done at a faster rate. Better results are obtained while using a mixture of NaOH and KOH. From the microscopic images of the machined surface, it was observed that material removal mechanism in G-ECDD is a combination of grinding action, electrochemical discharges, and chemical etching. Response surface methodology was adopted for studying the influence of process parameters on the performance of G-ECDD. The new technique of grinding aided electrochemical discharge drilling proved its potential to machine borosilicate glass and simultaneously offers good material removal rate, repeatability, and accuracy.


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