Electrothermal theory approach for numerical approximation of the μ-EDM process

A fundamental study of microelectric discharge machining (μ-EDM) based on the physics of single spark and electrothermal theory has been carried out. The machining phenomena in the μ-EDM process are investigated through simulations using finite element method. By creating the single-discharge crater, the topography is measured using an atomic force microscope and the simulation results compared with the experimental result. A temperature distribution along the radius and depth of the workpiece is thus reported. For verification purpose, single-discharge experiments with RC pulse circuit are performed with tungsten carbide as the electrode and stainless steel as the workpiece. The diameter-to-depth ratios of the crater obtained by the simulation and the experiments are 2.92 and 2.67, respectively. The simulation results are found to be in close agreement with experimental results.     

MACHINING OF SODA LIME GLASS USING ABRASIVE HOT AIR JET: AN EXPERIMENTAL STUDY

Abrasive Jet Machining is becoming one of the most prominent machining techniques for glass and other brittle materials. In this article, an attempt has been made to combine abrasive and hot air to form an abrasive hot air jet. Abrasive hot air jet machining can be applied to various operations such as drilling, surface etching, grooving and micro finishing on the glass and its composites. The effect of air temperature on the material removal rate applied to the process of glass etching and grooving is discussed in this article. The roughness of machined surface is also analyzed. It is found that the Material Removal Rate (MRR) increases as the temperature of carrier media (air) is increased. The results have revealed that the roughness of machined surface is reduced by increasing temperature of carrier media. The mechanism of material removal rate has been discussed with aid of SEM micrographs.     

Three-dimensional numerical simulation of microelectric discharge machining of Ti-6Al-4V

The International Journal of Advanced Manufacturing Technology - The aim of the present work is to develop a predictive thermal model based on heat transfer principle for the simulation of...     

Machining and Characterization of Multidirectional Hybrid Silica Glass Fiber Reinforced Composite Laminates Using Abrasive Jet Machining

Silicon - Machining of multidirectional Hybrid Fiber Reinforced Composite (HFRC) is a challenging task because of defects like matrix cracking, fiber pullouts, delamination, burr formation, and...     

Material removal characteristics of microslot (kerf) geometry in μ-WEDM on aluminum

This paper presents the formulation and solution of optimization of various process parameters for the selection of the best control settings on a microwire electrical discharge machining process. A factorial design model is used to predict the measures of performance as a function of various control settings. Analysis of variance is used to indicate the significant factors. Regression models relating the machining performance are established. The performance measures taken for the model are material removal rate (MRR), overcut, and surface roughness. At discharge energy of 2,645 μJ, maximum MRR of 0.0428 mm³/min and an overcut value of 69 μm are observed. With the value of discharge energy changing from 32 to 4,500 μJ, the Ra value of slot surface varied from 1.17 to 4.25 μm. The analysis gave the average erosion efficiency around of 27%, which showed high sensitivity to the selected discharge energy levels.     

Machining and Characterization of Channels and Textures on Quartz Glass Using μ-ECDM Process

Silicon - Applications of various glass materials like sodalime, borosilicate and pyrex are growing in the field of micro-electro mechanical systems. Quartz glass composes of pure silicon dioxide...     

A feasibility approach by simulated annealing on optimization of micro-wire electric discharge machining parameters

Due to the presence of large number of process variables and complicated stochastic nature, selection of optimum machining parameter combinations for obtaining higher material removal rate with minimum overcut and surface roughness is a challenging task in Micro Wire Electric Discharge Machining (μ-WEDM). The important parameters of Material Removal Rate (MRR), overcut and surface roughness are considered in this study of single pass μ-WEDM machining of aluminium. The system model is created with statistical based regression analysis using experimental data. This system model is employed to maximize the material removal rate and minimize the surface roughness and overcut using Simulated Annealing (SA) scheme. Finally consistency of the method is tested with trial values. The model is found as capable of predicting the response characteristics as a function of different control variables. Experiments are carried out to check the validity of the developed model and then optimal parametric combinations are searched out using an advanced optimization strategy.     

Theoretical investigations on the effect of system parameters in series hydraulic hybrid system with hydrostatic regenerative braking

As gasoline prices rise and the green movement grows, more fluid power companies are working to develop hydraulic hybrid drive trains for large trucks to passenger cars and wind turbines. The hydraulic hybrid drive system is more effective and efficient than traditional hybrid systems because the quantum of recuperation energy generated is comparatively very high. Series hydraulic hybrid system specially designed for stop-and-go vehicles captures energy as the vehicle brakes and puts the vehicle in motion, when the vehicle is restarted. Then the engine kicks in, once the energy captured gets depleted. The kinetic energy lost as heat energy during mechanical friction braking is recovered and stored in the hydraulic accumulator as potential energy during hydrostatic regenerative braking. This paper gives an insight in to the dynamic simulation results obtained using LMS AMESim tool and effect of various system parameters like pre-charge pressure and hydraulic pump/motor maximum displacement on system output power. Varying the pre-charge pressure of the accumulator and controlling the hydraulic pump/motor maximum displacement show significant improvement in the system output power. Maximizing the system output power indirectly leads to less fuel consumption and pollution reduction in hybrid vehicles.