Search

In this study, the duplex stainless steel is machined using a wire-cut electrical discharge machining process to overcome the issues of poor finishing, lower dimensional accuracy, and rapid wear of cutting tools in conventional machining processes. The higher rate of material removal and superior finish on the machine surface is dependent on kerf loss, which is expressed as the mean kerf width assessed at certain locations. Nevertheless, this approach is typically not effective in explicating the intricacies of true kerf loss due to the random selection of distinctive points. This work proposes an area-based measuring approach to quantify the kerf loss by taking into account any imperfections on the kerf wall. At the pulse on time of 20 μs and current of 3 A, the machining appears not stable. The pulse on time, current, and voltage of 12 µs, 1 A, and 80 V proved suitable for obtaining excellent dimensional precision. [ABSTRACT FROM AUTHOR]

The need for soft polymer (such as acrylonitrile butadiene rubber (ABR)) components in mating applications is increasing in several sectors, viz. automobile, mining, and marine, due to their viscoelastic nature with improved surface quality and tighter geometric tolerances. Therefore, this paper aims to compare the effect of cryogenic conditions on the performance parameters of the suspension-type abrasive water jet (S-AWJ) machining and investigate the kerf characteristics of the top and bottom surface by comparing the waviness of the cut profiles and abrasive contamination of the top surface near the vicinity of the slot under conventional (room temperature) and cryogenic (liquid nitrogen (LN2)) conditions. The study found that the use of LN2 positively affected the performance parameters (Kerf taper ratio (KTR) and material removal rate (MRR)) due to a sudden increase in Young's modulus and a decrease in elasticity of the machining zone. The cryogenic-assisted S-AWJ at the highest water jet pressure (WJP) (250 bar) produced better kerf characteristics through uniform and waviness-free top and bottom kerf profiles than the other experimental sequences. The use of LN2 resulted in the embrittlement of ABR, due to which less garnet abrasive particle contamination was observed during cryogenic-assisted S-AWJ machining. [ABSTRACT FROM AUTHOR]

The novelty of EDM machining as a drilling operation for composite materials means that there is no consensus on the influence of the parameters that optimise the final quality. For these reasons, a characterisation of the EDM drilling process of a unidirectional composite material has been developed. The influence of several cutting parameters has been related to the quality of the final hole obtained. Thus, macrogeometric aspects in terms of conicity and final diameter and microgeometric aspects in terms of surface quality have been evaluated. In addition, the final state of the material and the wear of the electrode have been evaluated by visual inspection, allowing the range of cutting parameters that offer the best performance to be established. Finally, a series of contour diagrams based on predictive models have been obtained to establish a direct relationship between input and output variables. [ABSTRACT FROM AUTHOR]

With steadily rising expanse of the engineering sector, demand for composite materials has been growing progressively over the years. Particularly, glass fiber reinforced polymer (GFRP) composites are being increasingly applied in various industries in the aerospace, automobile, and construction sectors due to their lightweight and superior performances. The present investigation examines the effect of traverse rate, jet pressure, standoff distance, and multi-walled carbon nanotubes (MWCNT), mixed with epoxy/glass fabric nanocomposites, on abrasive water jet machining (AWJM) responses, such as kerf taper (KT), surface roughness (Ra), material removal rate (MRR), entrance and exit delamination factor (DF) by using the Taguchi approach. The study has established that the addition of MWCNT in the GFRP laminates optimizes the machining responses. The investigation, using analysis of variance approach, revealed the most dominant parameter, which influences the machining performance of the composites. A significant enhancement in AWJM responses could be attained with optimal parameters. And also validates using surface examinations. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

WEDM (Wire electrical discharge machining) is a precision machining method for cutting electrically conductive materials. It is an unconventional machining process that produces precision parts that match the dimensional tolerances of our designs within the range of ±0.0001mm. As the residual stress results in premature failure of parts, the WEDM is preferred for hard to machine materials such as Inconel, Nickel, and other Super alloys. In the present paper, earlier and recent work was reviewed, segregated and evaluated on the effect of wire material, diameter, dielectric fluid, wire wear, pulse on and off times and machining characteristics such as kerf size, machining efficiency, material surface characteristics, etc. This paper also focused on hybrid and ultrasonic-assisted WEDM used for machining of different materials. This paper discussed the major research studies in WEDM. [ABSTRACT FROM AUTHOR]

In this study, microstructure, mechanical, and conductivity characteristics of Hardox 400 steel were changed with different heat treatments and effect of such characteristics on its machinability with Wire Electrical Discharge Machining (WEDM). Optical microscope examinations were performed to determine various characteristics, and additionally microhardness and conductivity measurements were conducted hereof. L18 Taquchi test design was conducted with three levels and four different parameters to determine the effect of such alterations on its machinability with WEDM and post-processing Cutting width (kerf), Surface roughness (Ra), Material removal rate (MRR) values were determined. Micro changes were ensured successfully by using applied heat treatments. The best kerf value was obtained from sample 6 which was tempered from 350 °C. The microstructure of this sample was composed of commonly α ferrite and few pearlites. The best Ra value was obtained from sample 3 which was tempered from 200 °C. The microstructure of this sample was composed of few α ferrite and commonly pearlites. The best MRR value was obtained from sample 5 which was tempered from 300 °C. The microstructure of this sample was composed of almost equally α ferrite and pearlites. Additionally the most effective parameters on Ra were determined as hardox and current. The most effective parameters on kerf and MRR were determined as time off and hardox. [ABSTRACT FROM AUTHOR]

This paper attempts at investigation of the feasibility of imparting a swirling motion to abrasive particles by introducing internal threads in the nozzle. In this investigation, a novel internal threaded nozzle was introduced in the abrasive jet machine to make holes on the carbon fiber reinforced polymer composites with the objective of reducing the machining time. This is a unique attempt of its kind and this innovation has brought down the machining time considerably and, as a consequence, higher material removal rate was obtained. Carbon fiber reinforced polymer composites are inhomogeneous and coarse in nature, and hence, the ease of machining and the machining time are always challenging. A morphological study was also made using an optical microscope to find the kerf width and kerf angles. The effect of two different nozzles on machining time, material removal rate, and kerf analysis on the carbon fiber reinforced polymer composite was investigated. It was found that machining time was reduced by 92% with novel internal threaded nozzle. The nozzle with internal threads also reduced the kerf angle of the machined hole. [ABSTRACT FROM AUTHOR]

The demand for micro products is rapidly increasing in chemical, marine and aerospace industries. The super alloys which have high strength and corrosion resistance properties play a major role. Hastelloy which is difficult to machine by the conventional processes can be machined by using AJM. Hastelloy C276 sheet of thickness 1mm has been drilled on the AJM test rig using variable process parameters. In this paper optimization of process parameters of Abrasive Jet Machining of Hastelloy C276 by RSM methodology is presented. The values obtained in RSM Analysis were compared with the Analysis of Variance (ANOVA). Various levels of experiments are conducted using L15 orthogonal array for both MRR and KERF. [ABSTRACT FROM AUTHOR]

Wire Electric Discharge Machining (WEDM) is one of the important non-traditional machining process used for machining difficult to machine materials like composites and inter-metallic materials, Intricate profiles. In the present work, the study has been made to optimize the process parameters during machining of Hastelloy -C-276 by wire-cut electrical discharge machining (WEDM). This paper presents an effective approach to optimize process parameters for Wire electric discharge machining (WEDM) is extensively used in tool and die industries. Precision and intricate machining are the strengths. While machining, time and surface quality still remains as major challenges. The input parameters are pulse on time (Ton), pulse off time (Toff), wire feed rate and current and voltage were changed during the process. The optimization of analysis is performed by using Genetic Algorithm (GA) method L-27 orthogonal array. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study on abrasive waterjet (AWJ) machining of the most commonly used titanium alloy, Ti-6Al-4V. Two types of machining operations, i.e. drilling (or piercing) and slotting, were conducted. For the drilling experiments, the influences of water pressure and drilling time were investigated. It was found that both the hole depth and diameter increased as drilling time increased but in a decreasing rate. An increase in the water pressure increased both the hole depth and the hole diameter. For the slot cutting, the influence of water pressure and the traverse speed were investigated. A slower traverse speed resulted in a deeper depth of cut. The kerf showed a taper shape with a wider entry on top, and the width decreased as jet cut into the material. At the bottom of the kerf, a pocket was generated. The variation of the depth of cut became insignificant when the traverse speed was increased. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on the effect and optimization of machining parameters on the kerf (cutting width) and material removal rate (MRR) in wire electrical discharge machining (WEDM) operations. The experimental studies were conducted under varying pulse duration, open circuit voltage, wire speed and dielectric flushing pressure. The settings of machining parameters were determined by using Taguchi experimental design method. The level of importance of the machining parameters on the cutting kerf and MRR is determined by using analysis of variance (ANOVA). The optimum machining parameter combination was obtained by using the analysis of signal-to-noise (S/N) ratio. The variation of kerf and MRR with machining parameters is mathematically modeled by using regression analysis method. The optimal search for machining parameters for the objective of minimum kerf together with maximum MRR is performed by using the established mathematical models. [Copyright &y& Elsevier]