scholarly journals ANALYSIS OF THE INFLUENCE OF TOOL ELECTRODE WEAR ON SURFACE QUALITY IN DIE-SINKING EDM TECHNOLOGY

2021 ◽  
Vol 2021 (2) ◽  
pp. 4388-4395
Author(s):  
LUBOSLAV STRAKA ◽  
◽  
PATRIK KUCHTA ◽  
Keyword(s):  
Indirect Method ◽  
Metal Particles ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Roughness Parameters ◽  
Machined Surface ◽  
Significant Deterioration ◽  
Undesirable Consequence ◽  
The Given

During the electro-erosive process, metal particles are gradually removed not only from the machined material but also from the tool electrode. Here, the removal of material from the tool electrode is generally considered to be an undesirable consequence of the electro-erosive process. The extent of this wear can be relatively accurately quantified using several indicators. Of these, the percentage of loss of the working part of the tool electrode has the highest informative value. The resulting quality of the eroded area after die-sinking EDM also depends on the magnitude of the given parameter. Therefore, based on experimental measurements, the paper aimed to describe the performed analysis of the influence of the wear of the shaped tool electrode on the quality of the machined surface after die-sinking EDM in terms of surface roughness parameters. The wear of the shape tool electrode in terms of volume loss was measured by the indirect method through weight loss. Experimental results showed that when machining tool steel with a finishing operation, a much lower wear rate of the shape tool electrode was recorded compared to the roughing operation. At the same time, it was found that when the shape tool electrode wear exceeds the level of about 8%, there is a significant deterioration of all qualitative indicators of the machined surface.

Machining Characteristics of EDM for Non-Conductive Ceramics Using Adherent Copper Foils

2010 ◽  
Vol 154-155 ◽  
pp. 794-805 ◽  
Author(s):  
Yao Jang Lin ◽  
Yan Cherng Lin ◽  
A Cheng Wang ◽  
Der An Wang ◽  
Han Ming Chow
Keyword(s):  
Removal Rate ◽  
Pyrolytic Carbon ◽  
Industrial Applications ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Machining Parameters ◽  
Machined Surface ◽  
Conductive Material ◽  
Conductive Ceramics ◽  
The Stability

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.

Study of Tool Electrode Wear in EDM Process

2015 ◽  
Vol 669 ◽  
pp. 302-310 ◽  
Author(s):  
Ľuboslav Straka ◽  
Slavomíra Hašová
Keyword(s):  
Material Removal ◽  
Electrical Discharge Machining ◽  
Electrical Energy ◽  
Metal Particles ◽  
Dielectric Fluid ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Electrical Discharges ◽  
Workpiece Material ◽  
Edm Process

Technology of Electrical Discharge Machining (EDM) uses thermal energy in material removal, in which is the electrical energy transformed, generated between the electrodes (tool and workpiece). The material removal occurs through the rapid periodic repetitive electrical discharges in the presence of dielectric fluid. By the action of electrical discharges occurs to decline not only particles of a metal workpiece material, but also to decline in a certain proportion of metal particles in tool electrode. The paper deals with the diagnosis the size of the electrode wear of tools made from copper and graphite used in EDM machining.

scholarly journals Improving of geometric precision in the manufacture of circular holes using technology WEDM

2019 ◽  
Vol 4 (1) ◽  
pp. 238-245
Author(s):  
Luboslav Straka ◽  
Gabriel Dittrich
Keyword(s):  
Process Parameters ◽  
Roughness Parameters ◽  
High Quality ◽  
Machined Surface ◽  
Geometrical Accuracy ◽  
Geometric Precision ◽  
Tool Setting ◽  
Circular Holes ◽  
Geometric Deviation

WEDM technology is among the final technology. It is characterized by the high quality of the machined surface. Therefore, a small geometric deviation from the desired shape, position, orientation or run out may have a significant impact on the functionality of the finished component. Its range is largely influenced by the accuracy of the applied electroerosion device, the precision of the workpiece and tool setting, the machining method, but also the combination of each other and the adjustment of all process parameters. They result in the final quality of the machined surface not only in terms of roughness parameters but also in terms of geometric precision of the machined surface. The aim of the paper was to describe the possibilities of improving the geometrical accuracy of WEDM with thin brass electrodes. At the same time, it contributes to an existing database of knowledge that defines the influence of selected aspects on the geometrical accuracy of the machined area in the production of circular openings.

scholarly journals Dynamic Control of Discharge Energy During WEDM for the Purpose of Eliminating Vibrations of the Wire Tool Electrode

2021 ◽  
Vol 29 (4) ◽  
pp. 260-265
Author(s):  
Ľuboslav Straka ◽  
Patrik Kuchta
Keyword(s):  
Electrical Discharge Machining ◽  
Production Systems ◽  
Dynamic Control ◽  
High Strength ◽  
Tool Electrode ◽  
Discharge Process ◽  
Machined Surface ◽  
The Wire ◽  
Wedm Process

Abstract Production in all industry fields is currently affected by new scientific and technical knowledge and the requirements for its rapid deployment. In many cases, the most modern and highly sophisticated technical systems are applied. Simultaneously, fully automated production systems are rather successfully used and progressive production technologies are implemented. In most cases, there is an integral part of a management system that operates the challenging technological processes. These processes would not be executable without the system’s precise control, which provides a suitable precondition for ensuring the high quality of manufactured products. However, the customer’s demanding requirements are not always met. These involve increased requests for the quality of the final product due to the reduction of the tolerance band and application of high-strength materials. This paper aims to describe one of the solutions by which it is possible to achieve a higher quality of the machined surface after wire electrical discharge machining (WEDM). The solution proposes that through dynamic management, the WEDM process eliminates the vibrations of the wire tool electrode and thereby achieves a substantial increase in the quality of the eroded area in terms of its geometric accuracy. With the support of an extensive database of information with precise exchange of information, the proposed system will allow to control the electro discharge process with regard to the optimal way of operation of the electro discharge machine on the basis of individually selected conditions.

Professional dilemmas for caregivers in Turkish home care settings in Germany

2014 ◽  
Vol 1 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Jan Basche
Keyword(s):  
Healthcare Services ◽  
Insurance Companies ◽  
Or Education ◽  
Migrant Communities ◽  
Caregiver Relationship ◽  
International Nursing ◽  
Nursing Literature ◽  
Intercultural Care ◽  
The Given

While calling for culturally sensitive healthcare services in migrant communities, the international nursing literature on intercultural care predominantly describes nursing staff as lacking cultural competences and immigrant customers as lacking cleverness to navigate the labyrinths of national healthcare systems. Congruences in language, culture and religion in the customer-caregiver relationship can decisively improve the quality of care. However, they do not automatically guarantee smooth working processes in monocultural in-home settings. On the contrary, new problems occur here for Turkish caregivers which are unknown to the legions of native professionals who feel challenged by migrants and which go beyond differences such as age, sex, income or education. While no cultural or religious brokering is necessary between customers and personnel in the given context in Germany, new challenges arise when caregivers are expected to legally broker between customers and insurance companies or doctors. Conflicting expectations of customers and management as well as their own colliding social and professional roles put the caregivers in a quandary and must be competently managed.

MODIFIKASI MODEL PEMBELAJARAN TEAM ASSISTED INDIVIDUALIZATION DENGAN STRATEGI PEMBELAJARAN TUGAS DAN PAKSA

2019 ◽  
Vol 2 ◽  
Author(s):  
Lea Christy Restu Kinasih ◽  
Dewi Fatimah ◽  
Veranica Julianti
Keyword(s):  
Cooperative Learning ◽  
Learning Strategies ◽  
Learning Process ◽  
Learning Model ◽  
Learning Models ◽  
Classroom Learning ◽  
Quality Of Learning ◽  
The Given

The selection and determination of appropriate learning strategies can improve the results to be obtained from the application of classroom learning models. This writing aims to discipline students to develop individual abilities of students to be more active in the learning process and improve the quality of learning. The learning process in Indonesia in general only uses conventional learning models that make students passive and undeveloped. In order for the quality of learning to increase, the Team Assisted Individualization learning model is combined with the task learning and forced strategies. The Team Assisted Individualization cooperative learning model is one of the cooperative learning models that combines learning individually and in groups. Meanwhile, task and forced learning strategies are strategies that focus on giving assignments that require students to complete them on time so that the learning process can run effectively. Students are required to do assignments according to the given deadline. This makes students become familiar with the tasks given by the teacher. Combining or modifying the learning model of the assisted individualization team with forced and forced learning strategies is expected to be able to make students more active, disciplined, independent, creative in learning and responsible for the tasks assigned. Therefore this method of incorporation is very necessary in the learning process and can be applied to improve the quality of learning in schools.

Integrating Safety-II into Safety Management

2021 ◽  
Author(s):  
Toni Wäfler ◽  
Rahel Gugerli ◽  
Giulio Nisoli
Keyword(s):  
Risk Factor ◽  
Safety Factor ◽  
Safety Management ◽  
Management Systems ◽  
Safety Management Systems ◽  
Safety Science ◽  
Human Failure ◽  
The Given ◽  
Freedom Of Action

We all aim for safe processes. However, providing safety is a complex endeavour. What is it that makes a process safe? And what is the contribution of humans? It is very common to consider humans a risk factor prone to errors. Therefore, we implement sophisticated safety management systems (SMS) in order to prevent potential "human failure". These SMS provide an impressive increase of safety. In safety science this approach is labelled "Safety-I", and it starts to be questioned because humans do not show failures only. On the contrary, they often actively contribute to safety, sometimes even by deviating from a procedure. This "Safety-II" perspective considers humans to be a "safety factor" as well because of their ability to adjust behaviour to the given situation. However, adaptability requires scope of action and this is where Safety-I and Safety-II contradict each other. While the former restricts freedom of action, the latter requires room for manoeuvring. Thus, the task of integrating the Safety-II perspective into SMS, which are traditionally Safety-I based, is difficult. This challenge was the main objective of our project. We discovered two methods that contribute to the quality of SMS by integrating Safety-II into SMS without jeopardizing the Safety-I approach.

Optimization and surface modification in electrical discharge machining of AA 6061/SiCp composite using Cu–W electrode

2015 ◽  
Vol 231 (3) ◽  
pp. 332-348 ◽  
Author(s):  
Balbir Singh ◽  
Jatinder Kumar ◽  
Sudhir Kumar
Keyword(s):  
Process Parameters ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Electrode Wear ◽  
Material Transfer ◽  
Machined Surface ◽  
Recast Layer Thickness ◽  
Pulse On Time ◽  
Pulse Off Time

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.

scholarly journals Adjustment of Wire Vibrations in Order to Improve Geometric Accuracy and Surface Roughness at WEDM

2021 ◽  
Vol 11 (11) ◽  
pp. 4734
Author(s):  
Ľuboslav Straka ◽  
Ivan Čorný
Keyword(s):  
Surface Roughness ◽  
Economic Efficiency ◽  
Acoustic Emissions ◽  
Tool Electrode ◽  
Geometric Accuracy ◽  
Dynamic Adjustment ◽  
Machined Surface ◽  
Minimal Impact ◽  
The Wire ◽  
Wedm Process

Although WEDM is one of the most precise finishing technologies, deviations from the required geometric shapes and surface roughness occur in the production of parts with rotary surfaces. Even though these shortcomings have only a minimal impact on planar cuts, the production of circular profiles is a different problem. One of the factors causing this poor quality is the vibration of the wire electrode. With appropriate vibration adjustment, it would be possible to achieve significant improvements of the eroded area quality, both in terms of geometric accuracy and in terms of surface roughness. This would significantly increase quality, enabling WEDM technology to compete with other technologies in terms of economic efficiency. Therefore, the proposed solution aims to provide a partial adjustment to the wire tool electrode vibrations, based on their sensing by the means of acoustic emissions or a laser beam, with subsequent dynamic adjustment of the actual technological parameter values. This way, the given solution will increase the production accuracy of circular holes, increase productivity, and ultimately provide an overall increase in the economic efficiency of the WEDM process. The article also presents the scheme of a control algorithm for monitoring and subsequent adjustments of the vibrations of the wire tool electrode during the electroerosion process in order to minimize geometric deviations of circularity, cylindricity and roughness of the machined surface.

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