Characterisation and modelling of tool electrode wear during planetary EDM of titanium grade 5 alloy

Author(s):  
Vishal John Mathai ◽  
Harshit K. Dave ◽  
Keyur P. Desai
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):  
Prathik Jain Sudhir ◽  
Ravindra Holalu Venkatadas ◽  
Ugrasen Gonchikar

Abstract Wire Electrical Discharge Machining (WEDM) provides an effective solution for machining hard materials with intricate shapes. WEDM is a specialized thermal machining process is capable to accurately machining parts of hard materials with complex shapes. However, selection of process parameters for obtaining higher machining efficiency or accuracy in wire EDM is still not fully solved, even with the most up-to-date CNC WED machine. The study presents the machining of Titanium grade 2 material using L’16 Orthogonal Array (OA). The process parameters considered for the present work are pulse on time, pulse off time, current, bed speed, voltage and flush rate. Among these process parameters voltage and flush rate were kept constant and the other four parameters were varied for the machining. Molybdenum wire of 0.18mm is used as the electrode material. Titanium is used in engine applications such as rotors, compressor blades, hydraulic system components and nacelles. Its application can also be found in critical jet engine rotating and airframes components in aircraft industries. Firstly optimization of the process parameters was done to know the effect of most influencing parameters on machining characteristics viz., Surface Roughness (SR) and Electrode Wear (EW). Then the simpler functional relationship plots were established between the parameters to know the possible information about the SR and EW. This simpler method of analysis does not provide the information on the status of the material and electrode. Hence more sophisticated method of analysis was used viz., Artificial Neural Network (ANN) for the estimation of the experimental values. SR and EW parameters prediction was carried out successfully for 50%, 60% and 70% of the training set for titanium material using ANN. Among the selected percentage data, at 70% training set showed remarkable similarities with the measured value then at 50% and 60%.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5600
Author(s):  
Sylwester Żelazny ◽  
Witold Żukowski ◽  
Dariusz Bogdał ◽  
Szczepan Bednarz ◽  
Wiktor Kasprzyk ◽  
...  

Superalloys provide high corrosion resistance and are widely used as high-performance materials in aerospace, automotive, chemical, and other industries. Herein, the investigation into the characteristics and properties of alloy waste; Inconel 625, Inconel 718, and Titanium Grade 5, from the automotive industry, was introduced as a result of a recovery in various processes. For this reason, the following procedures were carried as follows; the washing process to remove oil from the swarf was evaluated using several commercial agents and for the process of thermal disposal of processing fluids, a temperature of 900 °C was used in a muffle furnace without air access. The presented studies show that the commercially available series of washing agents did not modify the composition of the surface. However, the high temperatures during the calcination of oil residues are affecting the elemental composition of the alloys. According to the results of the analyses, it is not possible to remove 100% of the oil residues from alloy waste using washing agents based on light organic fractions; however, the effectiveness of this method reaches 99%. In this report, accurate SEM-EDS analyses show changes that occur on the surface after machining and removal of processing fluids. The NMR and GC/MS investigations indicate contaminants as a mixture of aliphatic and cycloaliphatic hydrocarbons with carbon numbers from C8–C30.


Author(s):  
Hao Tong ◽  
Jing Cui ◽  
Yong Li ◽  
Yang Wang

In 3D scanning micro electro discharge machining (EDM), the CAD/CAM systems being used in mechanical milling of numerical control (NC) are unable to be applied directly due to the particularity of tool electrode wear. Based on industry computer and RT-Linux software platform, a CAD/CAM integration system of 3D micro EDM is developed. In the developed CAD/CAM integration system, the hardware includes mainly a micro feed mechanism for servo control, XY worktable, a high frequency pulse power supply, monitoring circuits etc., and the functions consist of model design, scanning path planning and simulation, NC code generation and post processing, real-time compensating of tool electrode wear, and machining control of states and process. The method of double buffer storage is adopted to transmit numbers of NC machining data. Servo scanning EDM method is used to realize real-time electrode wear compensating and thereby 3D micro structures are machined automatically. The machining experiments are made about model design, parameters optimizing, and process control. The typical 3D micro structures with space curved surfaces and lines have been machined such as micro prism, micro half tube, camber correlation line, and so on. The machining process and results show that the CAD/CAM integration system has the characters of higher real-time, reliability, and general using.


2020 ◽  
Vol 142 (9) ◽  
Author(s):  
I. Valiente-Blanco ◽  
J. L. Perez-Diaz ◽  
J. L. Perez-del-Alamo ◽  
E. Diez-Jimenez

Abstract Linear bushings are a compact and reliable solution for mechanisms requiring relative linear displacement between moving parts. In this paper, we report the dependence of the coefficient of friction (COF) of polytetrafluoroethylene (PTFE) grease-lubricated bushings against a Ti6Al4 V (grade 5) alloy shaft at high temperatures up to 200 °C, for a motion speed of up to 0.47 m/s and a load pressure of 0.8 MPa. A proportional sensitivity of the COF with temperature is observed due to the change in the viscosity of the grease lubricant. Results of survival tests are also reported demonstrating a total sliding distance of 3200 m without maintenance and a total a total sliding distance of 10,200 m without critical failure.


Author(s):  
Shivraj Yeole ◽  
Nagabhushana Ramesh Nunna ◽  
Balu Naik Banoth

Electrical Discharge Micro Drilling (EDMD) is considered as one of the most effective method for machining difficult to cut and hard materials like titanium alloy. However, selection of process parameters for achieving superior surface finish, higher machining rate and accuracy is a challenging task in drilling micro-holes. In this paper, an attempt is made to optimize micro-EDM process parameters for drilling micro holes on titanium grade 19 alloy. In order to verify the optimal micro-EDM process parameters settings, material removal rate (MRR), electrode wear rate (EWR) and over cut (OC) were chosen as the responses to be observed. Pulse on time, pulse off time, electrode diameter and current were selected as the governing process parameters for evaluation by Taguchi method. Nine micro holes of 300 μm, 400 μm and 500 μm were drilled using L9 orthogonal array (OA) design. Optimal combination of machining parameters were obtained through Signal-to-Noise (S/N) ratio analysis. It is seen that machining performances like material removal rate and overcut are affected by the peak current whereas electrode wear is affected by peak current and electrode diameter. Morphology of the micro holes has been studied through SEM micrographs of machined micro-hole.


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