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Influence of EDM process parameters of novel Al7010/B4C/BN hybrid metal matrix nanocomposite

Dirisenapu Gopichand, Salavaravu Laxmanaraju, Dumpala Lingaraju

Composites Theory and Practice

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2023

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R. 23, nr 4

191--196

EN

In this present research work, the electrical discharge machining (EDM) characteristics of an Al7010/2%B4C/2%BN (the reinforcement particles are taken as wt.%) hybrid metal matrix nanocomposite (HMMNC) are discussed. The effect of the EDM process variables like the discharge current (I), pulse on time (Pon), pulse off time (Poff) and gap voltage (Vg) on the response characteristics like the material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) are presented. The results revealed that the MRR, TWR, and SR grew with an increase in Ip and Pon. MRR, TWR, and SR increased with a rise in Poff up to 25 μs then declined. MRR, TWR, and SR decreased with an increment in gap voltage. The highest MRR was observed for a discharge current of 8 A, Pon of 60 μs, Poff of 25 μs and Vg of 30 V. SR and TWR were the smallest at Ip of 2 A, Pon of 15 μs, Poff of 55 μs and Vg of 60 V. The scanning electron microscope (SEM) micrographs of the machined surfaces revealed voids, craters and micro cracks.

2

Evaluation of the Optimum Machining Stability of a Milling Tool with Different Flutes and Overhangs

Lin Yung-Chih, Wu Kung-Da, Shih Wei-Cheng, Hung Jui-Pin

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 2

56--64

EN

In machining practice, the selection of the tooling condition of the cutters is an important task for milling operation with better surface quality and material remove rates. This study was therefore aimed at evaluating the influence of the tooling condition, such as the flutes and overhang length, on the machining efficiency of a milling machine by using the machining stability analysis method. Essentially, the machining stability was calculated based on the measured frequency response functions of the milling cutter, while it was also affected by the changing milling tooling path. Therefore, the machining stabilities in different feeding directions, referred to as polar stability boundary, were evaluated to show the strength and weakness of a specific cutter in contouring machining. The current results show that the overhang length greatly affects the dynamic characteristics and the limited cutting depths of the milling cutter. The stability boundaries of the machining conditions can be enhanced by appropriately adjusting the overhang of the milling cutter. Besides, the 2-flute cutter shows a larger cutting depth for surface contouring as compared to the 4-flute cutter, which is expected to increase the material remove rate under stable machining. As a whole, this study provides valuable references for enhancing the machining efficiency through the use of different tooling conditions.

3

Electrical discharge machining of difficult to cut materials

Świercz R., Oniszczuk-Świercz D., Dąbrowski L.

Archive of Mechanical Engineering

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2018

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Vol. LXV, nr 4

461--476

EN

The development of industry is determined by the use of modern materials in the production of parts and equipment. In recent years, there has been a significant increase in the use of nickel-based superalloys in the aerospace, energy and space industries. Due to their properties, these alloys belong to the group of materials hard-to-machine with conventional methods. One of the non-conventional manufacturing technologies that allow the machining of geometrically complex parts from nickel-based superalloys is electrical discharge machining. The article presents the results of experimental investigations of the impact of EDM parameters on the surfaces roughness and the material removal rate. Based on the results of empirical research, mathematical models of the EDM process were developed, which allow for the selection of the most favourable processing parameters for the expected values of the surface roughness Sa and the material removal rate.

4

Electrode material on machined surface during spark erosion of Ti-6Al-4V (machined at low range parameters)

Thesiya D., Dave J., Rajurkar A.

Advances in Manufacturing Science and Technology

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2014

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Vol. 38, nr 4

39--51

EN

Investigation of the machining performance of the titanium alloy (Ti-6Al-4V) at low range parameters by the electrical discharge machining (EDM) using copper and graphite as electrodes with positive polarity. The objective of this paper is to investigate the peak current (A), servo voltage (V), on time (Ton), off time (Toff) and show the effects on material removal rate (MRR), electrode wear rate (EWR) and surface roughness (SR). Design of experiments (DOE) method by using Taguchi technique (L18) mixed level implemented. The validity test of the fit and adequacy of the proposed model has been carried out through analysis of variance (ANOVA).SR was set the lower the better to attain the optimum dimensional precision. Experimental results indicate that copper as a tool electrode shows a better surface roughness than a graphite electrode.

PL

W pracy przedstawiono analizę wyników badań obróbki elektroerozyjnej stopu tytanu Ti-6Al-4V w zakresie małej wartości wyładowań elektrycznych z zastosowaniem miedzianej i grafitowej elektrody spolaryzowanej dodatnio. Wyznaczono wpływ parametrów prądowych: natężenia, napięcia, czasu włączenia i wyłączenia na chropowatość powierzchni, prędkość usuwania materiału i zużycie elektrody. W badaniach stosowano zaawansowaną metodę DOE (ang. DOE – Design of Experiments) wyznaczania wpływu zmiennych wejściowych na wynik procesu poddanego analizie. Walidację metody badawczej oraz przyjętego modelu prowadzono z użyciem wariancji ANOVA. Analiza wyników badań potwierdziła, że elektroda miedziana jest lepszym narzędziem do obróbki elektroerozyjnej stopu tytanu.