Copper Coated Electrode by Fused Deposition Modelling (FDM) Process

Abstract

Electrode manufacturing significantly affects the machining cost and time of the Electrical Discharge Machine (EDM). Therefore, many researchers investigated the metallization of 3D-printed electrodes for EDM as an alternative method to improve electrode manufacturing throughout the years. This study aims to investigate the metallization by Aluminum-carbon (Al-C) paste. Furthermore, the copper deposition of the metalized electrode was examined for different acidic bath concentrations and sample immersion duration. This particular electrode can be used in Electrical Discharge Machine (EDM). The electrode was fabricated by a Fused Deposition Machine (FDM). The material used to fabricate the electrode was Polyethylene Terephthalate Glycol (PETG). Aluminum-carbon (Al-C) paste is used for surface preparation as the first metallization step. This metallization method is environmentally friendly as electroless metallization eliminates the etching process. The samples have dipped 5 wt% of copper sulfate CuSO₄ and 15 wt% of sulfuric acid H₂SO₄ for 24, 72 and 120 h for the copper deposition process. After the metallization, the characteristics of each sample were evaluated by scanning electron microscope (SEM), electrical performance measurement and microscopic testing. The average resistance for 24, 72 and 120 h were 1.0 Ω, 0.7 Ω, and 0.23 Ω respectively. The standard deviation was calculated for 24, 72 and 120 h, which were 0.5, 0.35 and 0.12 respectively. For the SEM observation, the presence of Cu on 24 h was not distinctly visible and the deposited Cu on the samples was 28.58%. For 72 h, the Energy Dispersive X-ray for the sample corresponds with 42.20% of Cu. Meanwhile, the growth of Cu deposition was visible for 120 h, where the Cu deposition was 80.85%. The microscopic testing for the thickness of Cu coated on the samples was measured. The average thickness for 24, 72 and 120 h were $8.6_{ - 1.96}^{ + 1.51} \;\upmu {\text{m}}$, $108_{ - 13.82}^{ + 13.19} \;\upmu {\text{m}}$ and $150_{ - 33.43}^{ + 10.82} \;\upmu {\text{m}}$ respectively. Based on the results provided from all the tests, the 120 h sample has better Cu deposition than 24 h and 72 h. From the results, the longer the samples dipped in the acidic bath, the more the Cu deposition occurred.