A Study of Fabricating Nano-W Colloid by Discharge Energy Enhancement of the micro-EDM System

Abstract

This study enhanced the discharge energy of an existing micro-electric discharge machining (EDM) system to provide the system with the ability to prepare nano-tungsten (nano-W) colloid. The energy- enhanced EDM system, referred to as the upgraded-micro-EDM system, enables spark discharge using tungsten wires immersed in deionized water to produce nano-W colloids. Compared with the chemical preparation method, the processing environment for preparing colloids will not have nanoparticle escape in this study. Among the nano-W colloids prepared using the upgraded-micro-EDM system and an industrial EDM system, the colloid prepared by the upgraded-micro-EDM system exhibited more favorable absorbance, suspensibility, and particle size. The colloid prepared by the upgraded-micro-EDM system with the pulse on time and off time of 10–10 µs had an absorbance of 0.277 at the wavelength of 315 nm, ζ potential of −64.9 mV, and an average particle size of 164.9 nm. Transmission electron microscope imaging revealed the minimum particle size of approximately 11 nm, and the X-ray diffractometer spectrum verified that the colloid contained only \({\text{W}}_{2.00}\) and W nanoparticles. Relative to industrial EDM applications for nano-W colloid preparation, the upgraded system boasts lower costs and smaller size, and produces nano-W colloid with superior performance. These advantages contribute to the competitiveness of electrical spark discharge method in the preparation of high-quality nano-W colloids.

NEAL: an open-source tool for audio annotation

“…NEAL makes use of several open-source R packages ( Attali, 2021 ; Bailey, 2022 ; Pedersen et al, 2021 ; Chang, 2021 ; Chang & Borges Ribeiro, 2021 ; Granjon, 2021 ; Perrier, Meyer & Granjon, 2022 ; Aden-Buie, 2022 ; Littlefield & Fay, 2021 ; Silva, 2021 ; Ligges et al, 2018 ; Sueur, Aubin & Simonis, 2008 ; Wickham, 2016 ; Garnier et al, 2021 ; Chang, Luraschi & Mastny, 2020 ; Schloerke, 2020 ; Wickham et al, 2021 ; Wickham, 2019 ; Firke, 2021 ; Xie, Cheng & Tan, 2021 ). The most notable are:…”