Micro electro discharge machining for nonconductive ceramic materials

In micro-electro discharge machining (micro-EDM) of nonconductive ceramics, material is removed mainly by spalling due to the dominance of alternating thermal load. The established micro-EDM models established for single spark erosion are not applicable for nonconductive ceramics because of random s...

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Main Author:	Ali, Mohammad Yeakub
Format:	Conference or Workshop Item
Language:	English English
Published:	2017
Subjects:	T Technology (General) TJ Mechanical engineering and machinery TN Mining engineering. Metallurgy TS Manufactures
Online Access:	http://irep.iium.edu.my/67969/ http://irep.iium.edu.my/67969/1/WSMCE%202017%20Guilin%20Keynote-1%20%28Prof%20Ali%29.pdf http://irep.iium.edu.my/67969/7/67969_MICRO%20ELECTRO%20DISCHARGE%20MACHINING%20-%20program.pdf

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recordtype	eprints
spelling	iium-679692018-12-05T08:00:33Z http://irep.iium.edu.my/67969/ Micro electro discharge machining for nonconductive ceramic materials Ali, Mohammad Yeakub T Technology (General) TJ Mechanical engineering and machinery TN Mining engineering. Metallurgy TS Manufactures In micro-electro discharge machining (micro-EDM) of nonconductive ceramics, material is removed mainly by spalling due to the dominance of alternating thermal load. The established micro-EDM models established for single spark erosion are not applicable for nonconductive ceramics because of random spalling. Moreover, it is difficult to create single spark on a nonconductive ceramic workpiece when the spark is initiated by the assisting electrode. In this paper, theoretical model of material removal rate (MRR) as the function of capacitance and voltage is developed for micro-EDM of nonconductive zirconium oxide (ZrO2). It is shown that the charging and discharging duration depend on the capacitance and resistances of the circuit. The number of sparks per unit time is estimated from the single spark duration s derived from heat transfer fundamentals. The model showed that both the capacitance and voltage are significant process parameters where any increase of capacitance and voltage increases the MRR. However, capacitance was found to be the dominating parameter over voltage. As in case of higher capacitances, the creation of a conductive carbonic layer on the machined surface was not stable; the effective window of machining 101 - 103 pF capacitance and 80 - 100 V gap voltage or 10 - 470 pF capacitance and 80 - 110 V gap voltage. This fact was confirmed EDX analysis where the presence of high carbon content was evident. Conversely, the spark was found to be inconsistent using parameters beyond these ranges and consequently insignificant MRR. Nevertheless, the effective number of sparks per second were close to the predicted numbers when machining conductive copper material. In addition, higher percentage of ineffective pulses was observed during the machining which eventually reduced the MRR. In case of validation, average deviations between the predicted and experimental values were found to be around 10%. Finally, micro-channels were machined on nonconductive ZrO2 as an application of the model. 2017-12-02 Conference or Workshop Item PeerReviewed application/pdf en http://irep.iium.edu.my/67969/1/WSMCE%202017%20Guilin%20Keynote-1%20%28Prof%20Ali%29.pdf application/pdf en http://irep.iium.edu.my/67969/7/67969_MICRO%20ELECTRO%20DISCHARGE%20MACHINING%20-%20program.pdf Ali, Mohammad Yeakub (2017) Micro electro discharge machining for nonconductive ceramic materials. In: 2nd World Symposium on Mechanical and Control Engineering (WSMCE 2017), 2nd-3rd Dec. 2017, Guilin, China. (Unpublished)
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English English
topic	T Technology (General) TJ Mechanical engineering and machinery TN Mining engineering. Metallurgy TS Manufactures
spellingShingle	T Technology (General) TJ Mechanical engineering and machinery TN Mining engineering. Metallurgy TS Manufactures Ali, Mohammad Yeakub Micro electro discharge machining for nonconductive ceramic materials
description	In micro-electro discharge machining (micro-EDM) of nonconductive ceramics, material is removed mainly by spalling due to the dominance of alternating thermal load. The established micro-EDM models established for single spark erosion are not applicable for nonconductive ceramics because of random spalling. Moreover, it is difficult to create single spark on a nonconductive ceramic workpiece when the spark is initiated by the assisting electrode. In this paper, theoretical model of material removal rate (MRR) as the function of capacitance and voltage is developed for micro-EDM of nonconductive zirconium oxide (ZrO2). It is shown that the charging and discharging duration depend on the capacitance and resistances of the circuit. The number of sparks per unit time is estimated from the single spark duration s derived from heat transfer fundamentals. The model showed that both the capacitance and voltage are significant process parameters where any increase of capacitance and voltage increases the MRR. However, capacitance was found to be the dominating parameter over voltage. As in case of higher capacitances, the creation of a conductive carbonic layer on the machined surface was not stable; the effective window of machining 101 - 103 pF capacitance and 80 - 100 V gap voltage or 10 - 470 pF capacitance and 80 - 110 V gap voltage. This fact was confirmed EDX analysis where the presence of high carbon content was evident. Conversely, the spark was found to be inconsistent using parameters beyond these ranges and consequently insignificant MRR. Nevertheless, the effective number of sparks per second were close to the predicted numbers when machining conductive copper material. In addition, higher percentage of ineffective pulses was observed during the machining which eventually reduced the MRR. In case of validation, average deviations between the predicted and experimental values were found to be around 10%. Finally, micro-channels were machined on nonconductive ZrO2 as an application of the model.
format	Conference or Workshop Item
author	Ali, Mohammad Yeakub
author_facet	Ali, Mohammad Yeakub
author_sort	Ali, Mohammad Yeakub
title	Micro electro discharge machining for nonconductive ceramic materials
title_short	Micro electro discharge machining for nonconductive ceramic materials
title_full	Micro electro discharge machining for nonconductive ceramic materials
title_fullStr	Micro electro discharge machining for nonconductive ceramic materials
title_full_unstemmed	Micro electro discharge machining for nonconductive ceramic materials
title_sort	micro electro discharge machining for nonconductive ceramic materials
publishDate	2017
url	http://irep.iium.edu.my/67969/ http://irep.iium.edu.my/67969/1/WSMCE%202017%20Guilin%20Keynote-1%20%28Prof%20Ali%29.pdf http://irep.iium.edu.my/67969/7/67969_MICRO%20ELECTRO%20DISCHARGE%20MACHINING%20-%20program.pdf
first_indexed	2023-09-18T21:36:30Z
last_indexed	2023-09-18T21:36:30Z
_version_	1777412855873667072

Micro electro discharge machining for nonconductive ceramic materials

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