Effect of Laser Parameters on Sequential Laser Beam Micromachining and Micro Electro-Discharge Machining (original) (raw)

An analysis to enhance the machining performance of micro-EDM for drilling of blind micro-hole using ANN

The high demand for compact and multitasking devices in the market has been a driving force behind the growing interest in microfabrication techniques. These techniques have wide-ranging applications in many industries, including aerospace, automobile, electronics, and defense. Micro electrical discharge machining (µEDM) techniques have the unique ability to produce highly precise and intricate features on small components, which has further fueled the demand for such products. However, with the increasing demand for micro-featured products, there is a pressing need to enhance the process capability of µEDM process. This work aims to address this need by focusing on enhancing the performance of µEDM by varied process parameters and materials such as copper, brass, and tungsten carbide for the drilling of blind micro holes. Surface roughness (SR) and material removal rate (MRR) are the main performance factors taken into account in this investigation. Notably, the minimum SR was achi...

A Review on Optimization of Micro EDM Machining Performances

Now these days there is a massive requirement in the production of microstructures by a unconventional method. Micro-EDM (µEDM) is a widely accepted unconventional machining option in which material erosion takes place from work-piece using a sequence of electrical spark. This method is used to manufacture micro-parts with the range of 50 μm-100 μm. This paper studied the optimization of various process parameters namely gap voltage, peak current and pulse duration to attain suitable µEDM performance measures such as Material Removal Rate (MRR), low Electrode Wear (EW) and good surface morphology of the microstructure accepted from µEDM machining process.

Optimization of EDM process in machining micro holes for improvement of hole quality

Electrical discharge machining (EDM) or micro EDM found successful for production of micro holes on ceramics, hard metal and alloys. In the present study, experimental investigation and parametric optimization are carried out on EDM process for producing micro holes of diameter 500 μm on stainless steel (grade 304).Current (I), gap voltage (V) and pulse on time (Ton) are considered as process parameters and are optimized for improving hole quality [i.e., overcut (OC) and taper angle (θ)]. Statistical regression models are developed for predicting OC and θ and effects of parameters are studied using surface plots. The optimal parameters are obtained for single as well as multiple performance characteristics. The traditional Taguchi analysis is used for optimization of each objective individually. This work presents the application of Taguchi optimization for simultaneous minimization of over cut (OC) and taper angle (θ) for improvement of hole quality in drilling micro holes.The optimal level of factors based on analysis of means (ANOM) with highest signal to noise (S/N) ratio is found as (i.e., I1 − V3 − Ton2). This corresponds to parametric combination being 10 A, 50 V and 150 μs for I, V and Ton respectively that produce improved hole quality with minimum overcut and taper angle. The obtained result is compared with desirability analysis and found that it is closer.

Micro-Electro Discharge Machining of Holes and Grooves: AnAssessment of Process Parameters

International Journal of Engineering and Technology

The need for a better cooling purpose in bio medical, electronics, microprocessors and radars has attracted many researchers. Since, microchannels fulfil this objective it's machining through different micro machining techniques requires more skill and knowledge. Micro electrical discharge machining (EDM)is considered as one of the advanced methods of machining micro tools, dies, channels, grooves etc. More emphasis should be given to this machining process so that complicated geometries with least effort can be produced. In the present work critical study has been done on different tool materials as well as workpiece materials used on machining work table in micro EDM with different new strategies of machining will be helpful to enhance understanding of the subject. Along with this a direct method of getting tools for making micro holes and grooves on workpiece is suggested. Keyword-Microchannel, tool electrode, microholes, microgrooves, material removal rate, tool wear I. INTRODUCTION In recent years micro-electro discharge machining(EDM) gained a significant role in fabrication of very complex microstructures like micro holes, channels, grooves and 3-D structures irrespective of the hardness of the workpiece material [1]. This technology helps to remove micro particles easily from electrically conductive materials due to generation of spark which associated with melting and vaporization of materials from the surface of workpiece [2].As it is a contactless process that exerts very small force on both electrode and specimen, it minimizes the chances to develop thermal stresses. The major difference between macro and micro electro discharge machining is well defined by the plasma size[3].µ wire EDM, µ-die sinking,µ-milling and drilling are the different varieties of micro EDM with respect to tool and tool kinetics[4].In micro wire EDM the electrode used is either tungsten or copper wire of diameter 25-300µm that cut through the specimen where as in micro die sinking EDM the tool electrode is the replica to be produced in workpiece[5]. To get a fine electrode, reverse polarity is done where material generally gets removed from electrode instead of workpiece. This process generally called as wire electro discharge grinding or WEDG. After getting desired shape of electrode by WEDG that can be used to drill small hole on workpiece called EDM drilling. In EDM milling cylindrical electrode is rotated which follow a path through the workpiece to produce required geometry. Micro EDM is the machining on EDM where sizes of the tool, discharge energy are in micro levels[6]. There are large research possibilities in this area as it has very wide applications[7]. Micromachining in EDM has been extensively studied by many researchers and presented in [8,9,10]. Sato et al [11] were the first to propose micro hole drill by EDM for ink-jet nozzles of printers.The holes produced are of diameter 15 to 300 µm. In addition to micromachining microelectrodes can be generated by wire electro discharge grinding (WEDG) [12,13].Tungsten electrodes with diameter 300µm were machined to form 200µm using WEDG to produce microstructures on single crystal P-type boron doped silicon as it is widely used in semiconductors [14]. Masuzawa et al [15] proposed a system for drilling microholes by EDM. Anew technology is developed where micro holes and shafts are produced of 5 µm in diameter [16].Different materials used as electrodes in EDM are of different shapes of copper,tungsten,graphite, silver and brass[17,18]. Mohite et al [19] developed a EDM tool for fabrication of leaf shape microchannel heat sink of Aluminium 6061 and optimize the process parameters by using orthogonal array Taguchi's analysis of variance (ANNOVA) and signal to noise ratio (S/N ratio).Yan et al [20] found fabrication of tool electrode for micro hole fabrication by die sinking EDM as the most difficult job. An experimental procedure is followed by them to get a small, fine and straight cupper tool electrode to make micro holes in carbide workpiece.Yu et al [21] modified commercial EDM machine to get planetary motion of tungsten electrode used as tool to produce high aspect ratio micro holes and blind non circular holes on stainless steel AISI 304L workpiece material and at the same time blind triangular, square,pentagonal micro holes are achieved by offsetting the tool path by 15 to 20 µm. Jahan et al [22]

Dual-Stage Artificial Neural Network (Ann) Model for Sequential Lbmm-μedm Based Micro Drilling

2021

A sequential process combining laser beam micromachining(LBMM) and micro electrodischarge machining (μEDM) for the micro-drilling purpose was developed to incorporate both methods' benefits. In this sequential process, a guiding hole is produced through LBMM first, followed by μEDM applied to that same hole for more fine machining. This process facilitates a more stable, efficient machining regime with faster processing (compared to pure μEDM) and much better hole quality (compared to LBMMed holes). Studies suggest that strong correlations exist between the various input and output parameters of the sequential process. However, a mathematical model that maps and simultaneously predicts all these output parameters from the input parameters is yet to be developed. Our experimental study observed that the μEDM finishing operation's various output parameters are influenced by the morphological condition of the LBMMed holes. Hence, an artificial neural network(ANN) based dual-sta...

Experimental investigation for improvement of micro-machining performances of µ-ECDM process

Materials Today: Proceedings, 2020

Micro-parts and devices are manufactured by various processes like electrochemical discharge micromachining process (m-ECDM) for utilizing in modern industry. In this paper an automated spring feed m-ECDM set up with template guided CAM follower mechanism in tool holding unit has been applied for improving micro-machining performances. This paper focuses mainly on the parametric effects of applied voltage (V), pulse frequency (f), duty ratio (%) and electrolyte concentration (wt%) on different machining performances characteristics such as material removal rate, overcut, heat affected zone, surface roughness and machining depth. The paper also includes the analysis on surface roughness integrity of micro-channel cutting on silica glass (SiO 2 + NaSiO 3) by m-ECDM process. Application of microchannels has been reported for utilization as lab on chips or as micro-fluidic channel and achieved better micro-machining performances using spring feed mechanism at the parametric combination of 50 V/10wt%/200 Hz/45% duty ratio/40 mm inter electrode gap (IEG) by m-ECDM process during microchannel cutting.

Simultaneous optimisation of multiple performance characteristics in micro-EDM drilling of titanium alloy

The International Journal of Advanced Manufacturing Technology, 2012

Micro-electrical discharge machining (micro-EDM) has become a widely accepted non-traditional material removal process for machining conductive and difficultto-cut materials effectively and economically. Being a difficult-to-cut material, titanium alloy suffers poor machinability for most cutting processes, especially the drilling of micro-holes using traditional machining methods. Although EDM is suitable for machining titanium alloys, selection of machining parameters for higher machining rate and accuracy is a challenging task in machining micro-holes. In this study, an attempt has been made for simultaneous optimization of the process performances like, metal removal rate, tool wear rate and overcut based on Taguchi methodology. Thus, the optimal micro-EDM process parameter settings have been found out for a set of desired performances. The process parameters considered in the study were pulse-on time, frequency, voltage and current while tungsten carbide electrode was used as a tool. Verification experiments have been carried out and the results have been provided to illustrate the effectiveness of this approach.

Review of Optimized Technologies for Micro Machining

International Journal of Engineering Research & Technology (IJERT) IJERT , 2015

Micromachining is the most basic technology for the production of miniaturized parts and components. It includes bulk micromachining processes which produce structures inside a substrate and surface micromachining processes which are based on the deposition and etching of different structural layers on top of the substrate. On the other hand, in "mechanical/conventional" micromachining the material removal process resembles macroscopic machining processes such as drilling, milling and others. From such a point of view, micromachining encompasses microelectromechanical systems (MEMS), microsystems technologies (MST) and, in addition, includes processes related to the production and packaging of microsystems [MAS 00a]. Micromachining by precision technology such as 3D microEDM, microlaser machining, microcutting, microgrinding, etc. can produce microscopic and mesoscopic mechanical structures of complex shapes.