The high strength and hard-to-cut materials can be easily machined by using modern machining methods. It is important to introduce the efforts on enhancing the process for improving the machining quality. In the present investigation, an effort was made to analyze the effects of micro-size Al2O3 particles mixed into Kerosene as the dielectric under different powder concentrations on machining titanium alloy in Electrical Discharge Machining (EDM). Response Surface Methodology (RSM) based algorithm utilized to analyze the performance measures by considering machining time with Cost of Goods Manufactured (COGM) method in Powder Mixed Electro Discharge Machining (PMEDM) process. It was found that the micron size powders can significantly help to enhance the surface quality of the Ti-6Al-4V during machining in the PMEDM process. The presence of carbon, oxygen elements and the formation of surface oxides and carbides has been found due to the decomposition of dielectric fluid in the PMEDM process. The lower deep cavities and uniform of PMEDM’s surface have been produced by added Al2O3 powder into the EDM process owing to lower surface cracks density, conductivity.

Investigation of surface quality in Cost of Goods Manufactured (COGM) method of μ-Al2O3 Powder-Mixed-EDM process on machining of Ti-6Al-4V

Adding Al and Al2O3 powder creates electrical discharge machining (EDM) in a significant machining gap with stable condition. Practically, it is almost impossible to distribute powder particles evenly into the plasma channel. This study investigates the intermolecular process while the plasma channel’s pressure and temperature are changed. In our research, surfactant Tween 80® and its effects on intermolecular forces (IMF) through the plasma channel were investigated to evaluate surface quality. In the first phase of our research, output parameters ran at three experimental blocks (without surfactant, with 21.81 g/l of surfactant, and 43.3512 g/l of surfactant) in 17 runs while adding Al and Al2O3 powders with the design of experience (DOE) method by Design Expert software. Decomposition phenomena (DP), adhesion phenomena (AP), and nonuniform distribution (NUD) of Al and Al2O3 powders demonstrated how new molecules (aluminum trihydride, aluminic acid, methyl(methylene)aluminum, hydroxy(methyl)aluminum hydride, hydroxy(methylene)aluminum, and methyl(oxo)aluminum) were created on the surface element composition. In our experiment, powders’ even distribution when we decomposed Al and Al2O3 created a more stable plasma channel. Consequently, it led to a more balanced heat transfer on the electrodes’ surface. We used scanning of surface quality by field emission-scanning electron microscopy (FE-SEM), electron dispersive spectrum (EDS), and mapping and have shown how to improve the surface defects (hole, crack, and globule). In the second phase of our research, we investigated the intermolecular forces (IMF) on Al–O bond and Al–Al bond. The percentage of elements obtained by mapping analysis of cross-section illustrated that oxygen and aluminum had increased notably when we used Al powder. Considering physical, chemical, metallurgical, and machining time management (MTM) of PM-EDM, we demonstrated that the fine finishing surface improved by 217.7% at Ip = 15 A and Ton = 50 μs and Cp = 5 g/l when the surfactant was added. We compared the best-optimized points in the final phase of our work and measured the recast layer thickness (RLT) after adding Al and Al2O3. As a result, the RTL was removed entirely when Al was added to the dielectric. We have shown that MRR (g/h) and TWR (g/h) were decreased by 5.23 and 113.36%, and SR (Ra) and machining time were increased by 21.75 and 50.84%, respectively. We note that high strength-to-weight ratio and corrosion resistance are essential for many industries, particularly aerospace and biomedical industries. We believe that these industries can potentially benefit from our study.

Study of surfactant effects on intermolecular forces (IMF) in powder-mixed electrical discharge machining (EDM) of Ti-6Al-4V

Electrical discharge machining (EDM) is known as one of the well-defined advanced manufacturing techniques. The electro-thermal property of EDM enables us to capture the electrical and thermal changes within the plasma channel. Our research has studied the impact of the electro-thermal of the plasma channel on surface integrity. We have analyzed the changes in the plasma channel by considering its physical characteristics based on the EDM’s input parameters such as discharge current (I), pulse-on time (Ton), and concentration of added Al powder (Cp). In our experiment, adding Al powder decreased the dielectric resistance of kerosene. Furthermore, our mathematical and physical model demonstrated that adding powder had a positive effect up to 2.5 g/l. Moreover, the uneven distribution of powders into dielectric caused unstable discharge on the surface. We also studied the defects and changes of the plasma channel’s features by using field emission scanning electron microscopy (FE-SEM). The consequence of the plasma channel changes led to the crack’s disappearance entirely when the Al powder was used. It should be noted that with Ti-6Al-4V, it is hard to machine material, which is usually due to low thermal conductivity and its volume-specific heat. In our study, the fast-cooling rate created a diffusionless acicular martensitic microstructure, which led to a distorted hexagonal close-packed (HCP) crystal structure with the designation α′. This occurred while a high rate of quenching martensitic α′ was formed. The plasma channel creates a recast layer, which was affected by metallurgical changes within the EDM process. By using electron dispersive scanning (EDS) method and elemental mapping, we observed that the cross-section of the workpiece in the HAZ area led to the optimized oxidization, carbonization, and degree of fragility on the surface. Moreover, as the rate of the current intensity increased from 15 to 20-25A, the machining time improved by 16%, 12%, and 7%, respectively. Our experiment is consistent with our proposed mathematical model, and it can have practical applications, especially in medical, aerospace, and automobile industries. To the best of knowledge, our mathematical model that we have proposed for our experiment detects appearance and disappearance of metallurgical defects.

Mathematical and physical modeling of FE-SEM surface quality surrounded by the plasma channel within Al powder-mixed electrical discharge machining of Ti-6Al-4V

Electric discharge machining (EDM) is a nontraditional machining process based on the thermal erosion of the electrically conductive workpiece and tool electrodes. The product cost manufactured by ...

Review on tools and tool wear in EDM

The goal of this work is to shed light on the importance and application of FDM (Fused Deposition Modelling) in the production of electrodes for die-sinking EDM (Electrical Discharge Machining). A literature-based survey is conducted, and it is discovered that the applicability of FDM for manufacturing EDM electrodes has received little attention. The quantity of articles on this issue is exceedingly low in conventional data bases such as Web of Science and Scopus. The purpose of this study is to offer relevant investigations and demonstrate the convenience, merit, and limitations of the method used. The review offered in this work is intended to assist researchers, practitioners, and scientists in making informed decisions on which method to use to meet their needs. The authors have been inspired by the study trend to encourage scholars and researchers to investigate the applicability of the FDM technique in the fabrication of EDM electrodes further. The review is based on the most recent database from Web of Science, Scopus, and Google Scholar, using the keywords FDM/Fused Deposition Modeling and AM/Additive Manufacturing.

A critical insight into the use of FDM for production of EDM electrode

Rapid prototyping (RP) is a collection of techniques, and it is used in many industries to make a robust model of a mechanical sample instantly. RP is usually implemented by employing 3D printing or additive manufacturing (AM) technology with three-dimensional modeling. In the context of RP, rapid tooling (RT) is the result of applying the RP with non-conventional tooling. RT causes many discharge channels between the electrode in electro-discharge machining (EDM). In our study, acrylonitrile butadiene styrene is coated with a thin layer of copper and is used as an electrode tool in powder mixed electro-discharge machining (PM-EDM). We have employed the fused deposition modeling (FDM) method of rapid prototyping to improve the conductivity of the electrode tools for the PM-EDM. Cost, machining-time, and the quality of the surface are the significant outputs of the PM-EDM process for the fabrication of tools in sensitive industries. In our present research, a new kind of electrode is compared with a solid electrode with powder and without powder. Material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) have been measured for both scenarios. In this method, peak current, pulse-on time, and concentration of aluminium powder are the input parameters. We have also added a surfactant on kerosene for separating and distributing the powders. Our study demonstrates that the RP electrodes have the potential for utilizing the PM-EDM tools with complex shapes. The conventional processes do not make these complex shapes. Indeed, comparing the results of the output parameters in our proposed method with the PM-EDM existing methods indicates an improvement for MRR, TWR, and SR, by 33%, 31%, and 77%, respectively. Hence, the average surface quality, which is created by the PM-EDM, has been substantially improved. Thus, our proposed method is cost-effective, and it can be used to create various complex topologies, potentially in the medical and aerospace industries.

Powder mixed-electrical discharge machining (EDM) with the electrode is made by fused deposition modeling (FDM) at Ti-6Al-4V machining procedure

Sensor selection is an essential aspect of blind spot detection (BSD) systems. Indeed, we must choose the sensors appropriately to accomplish high accuracy and performance in any driving condition. Each sensor has exclusive properties which are suitable for a few specific circumstances. Therefore, a comprehensive study is warranted to determine the optimum number of sensors and the type of sensors for BSD. Although sensors have some deficiencies which can deteriorate the whole system's performance, a combination of multiple types of sensors together with data fusion methods in most cases can substantially compensate for sensors imperfection. In this paper, we have concentrated on multi-sensor fusion in BSD system and its advantages which cannot be achieved in a single-sensor BSD system. A sensing structure for the BSD system is proposed considering the indispensable factors in BSD coupled with sensors constraints, features, and specifications.

Sensing Structure for Blind Spot Detection System in Vehicles

Sensors are the quintessential part of Blind Spot Detection (BSD) systems, which have a profound effect on the performance of the system. Every sensor has its unique deficiencies that can deteriorate the performance of the system under grievous circumstances. Hence, making vital tasks in BSD such as object detection arduous. Indeed, previous studies have demonstrated that data fusion techniques can diminish the adverse effects of sensors and improve detection accuracy in the BSD system. One of the main advantages of data fusion is to improve detection accuracy and reduce the processing time by multiple sensors cooperation. We propose a BSD model that objects are detected in consecutive time intervals in the BSD system. Then, association techniques are employed for multi-sensor fusion since all sensors data are not ordinarily ready for fusion simultaneously. It should be noted that the orthodox approach in data association techniques in BSD often includes a global nearest neighbor, joint probabilistic data association, and multiple hypothesis tests. We simulate and compare these techniques by tracking multiple targets and multi-sensor fusion using virtual data in MATLAB. Furthermore, we illustrate that our multi-sensor fusion detection accuracy in the BSD system is augmented compared to a single sensor BSD system.

Mohammad Khoshnevisan

Papers

Powder mixed-electrical discharge machining (EDM) with the electrode is made by fused deposition modeling (FDM) at Ti-6Al-4V machining procedure

Study of surfactant effects on intermolecular forces (IMF) in powder-mixed electrical discharge machining (EDM) of Ti-6Al-4V

Mathematical and physical modeling of FE-SEM surface quality surrounded by the plasma channel within Al powder-mixed electrical discharge machining of Ti-6Al-4V

Sensing Structure for Blind Spot Detection System in Vehicles

Blind Spot Detection System in Vehicles Using Fusion of Radar Detections and Camera Verification