Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond

Electrical Discharge Machining (EDM) is a non-contact machining process that has become famous in machining of Polycrystalline Diamond (PCD). PCD is typically used as a cutting tool for aerospace and automotive industries as the material has high hardness (~80GPa) and strength (~60Gpa). However, low...

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Main Author: Ahmad, Muhammad Ariff Haikal
Format: Thesis
Language:English
English
English
Published: 2019
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spelling my-uthm-ep.5752021-08-05T03:41:15Z Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond 2019-02 Ahmad, Muhammad Ariff Haikal HD7260-7780.8 Industrial hygiene. Industrial welfare Electrical Discharge Machining (EDM) is a non-contact machining process that has become famous in machining of Polycrystalline Diamond (PCD). PCD is typically used as a cutting tool for aerospace and automotive industries as the material has high hardness (~80GPa) and strength (~60Gpa). However, low electrical conductivity (~10−13 S/m) and high melting temperature (3400oC) of PCD has caused slower EDM process. This investigation is purposely designed to investigate the EDM performance, machined surface and erosion mechanism of PCD in the influence of different types of electrode which are Copper-Nickel (Cu-Ni) and Copper (Cu) in roughing and finishing condition. Two levels of full factorial with eight center points and two replication technique was used to study the influence of main and interaction effects of the machining parameter. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Raman spectroscopy and oscilloscope were used for the mechanism analysis. In roughing condition, though 65% slower material removal rate (MRR) was obtained, Cu-Ni electrode produced better electrode wear ratio (EWR) of up to 500% in comparison to ordinary electrode. This is because lower electrical and thermal conductivity of Cu-Ni electrode produces high percentages of arching (immature discharge) which is inadequate to produce better MRR compared to Cu electrode. Meanwhile, different phenomena occurred in finishing condition in which the newly proposed electrode of Cu-Ni gave positive impact to the MRR. It is interesting as the Cu-Ni produced 14% higher MRR than the Cu electrode with its higher short circuiting rate. Cu-Ni also recorded the lowest surface roughness (Ra) value with 16% better than the best Ra produced by Cu electrode. These phenomena occurred due to the high interaction between the catalyst materials of nickel and diamond during short circuiting as supported by the chemical analysis. Due to the EDX analysis, the migration of catalyst materials into PCD was significant in finishing condition and it indicated that the catalyst electrode accelerated the graphitization process of PCD. 2019-02 Thesis http://eprints.uthm.edu.my/575/ http://eprints.uthm.edu.my/575/1/24p%20MUHAMMAD%20ARIFF%20HAIKAL%20AHMAD.pdf text en public http://eprints.uthm.edu.my/575/2/MUHAMMAD%20ARIFF%20HAIKAL%20AHMAD%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/575/3/MUHAMMAD%20ARIFF%20HAIKAL%20AHMAD%20WATERMARK.pdf text en validuser mphil masters Universiti Tun Hussein Onn Malaysia Fakulti Kejuruteraan Makanikal dan Pembuatan
institution Universiti Tun Hussein Onn Malaysia
collection UTHM Institutional Repository
language English
English
English
topic HD7260-7780.8 Industrial hygiene
Industrial welfare
spellingShingle HD7260-7780.8 Industrial hygiene
Industrial welfare
Ahmad, Muhammad Ariff Haikal
Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
description Electrical Discharge Machining (EDM) is a non-contact machining process that has become famous in machining of Polycrystalline Diamond (PCD). PCD is typically used as a cutting tool for aerospace and automotive industries as the material has high hardness (~80GPa) and strength (~60Gpa). However, low electrical conductivity (~10−13 S/m) and high melting temperature (3400oC) of PCD has caused slower EDM process. This investigation is purposely designed to investigate the EDM performance, machined surface and erosion mechanism of PCD in the influence of different types of electrode which are Copper-Nickel (Cu-Ni) and Copper (Cu) in roughing and finishing condition. Two levels of full factorial with eight center points and two replication technique was used to study the influence of main and interaction effects of the machining parameter. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Raman spectroscopy and oscilloscope were used for the mechanism analysis. In roughing condition, though 65% slower material removal rate (MRR) was obtained, Cu-Ni electrode produced better electrode wear ratio (EWR) of up to 500% in comparison to ordinary electrode. This is because lower electrical and thermal conductivity of Cu-Ni electrode produces high percentages of arching (immature discharge) which is inadequate to produce better MRR compared to Cu electrode. Meanwhile, different phenomena occurred in finishing condition in which the newly proposed electrode of Cu-Ni gave positive impact to the MRR. It is interesting as the Cu-Ni produced 14% higher MRR than the Cu electrode with its higher short circuiting rate. Cu-Ni also recorded the lowest surface roughness (Ra) value with 16% better than the best Ra produced by Cu electrode. These phenomena occurred due to the high interaction between the catalyst materials of nickel and diamond during short circuiting as supported by the chemical analysis. Due to the EDX analysis, the migration of catalyst materials into PCD was significant in finishing condition and it indicated that the catalyst electrode accelerated the graphitization process of PCD.
format Thesis
qualification_name Master of Philosophy (M.Phil.)
qualification_level Master's degree
author Ahmad, Muhammad Ariff Haikal
author_facet Ahmad, Muhammad Ariff Haikal
author_sort Ahmad, Muhammad Ariff Haikal
title Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
title_short Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
title_full Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
title_fullStr Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
title_full_unstemmed Investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
title_sort investigation on removal mechanism in catalytic aided electrical discharge machining of polycrystalline diamond
granting_institution Universiti Tun Hussein Onn Malaysia
granting_department Fakulti Kejuruteraan Makanikal dan Pembuatan
publishDate 2019
url http://eprints.uthm.edu.my/575/1/24p%20MUHAMMAD%20ARIFF%20HAIKAL%20AHMAD.pdf
http://eprints.uthm.edu.my/575/2/MUHAMMAD%20ARIFF%20HAIKAL%20AHMAD%20COPYRIGHT%20DECLARATION.pdf
http://eprints.uthm.edu.my/575/3/MUHAMMAD%20ARIFF%20HAIKAL%20AHMAD%20WATERMARK.pdf
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