A Study of Nano-Tungsten Colloid Preparing by the Electrical Spark Discharge Method

Abstract

This study developed an energy-enhanced (ee)-micro-electric discharge machining (EDM) system for preparing nano-tungsten (nano-W) colloids. This 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 in this study prevented nanoparticle escape. Among the nano-W colloids prepared using the ee-micro-EDM system and an industrial EDM system, the colloid prepared by the ee-micro-EDM system exhibited a more favorable absorbance, suspensibility, and particle size. The colloid prepared by the ee-micro-EDM system with a pulse on time and off time of 10–10 μs had an absorbance of 0.277 at a wavelength of 315 nm, ζ potential of −64.9 mV, and an average particle size of 164.9 nm. Transmission electron microscope imaging revealed a minimum particle size of approximately 11 nm, and the X-ray diffractometer spectrum verified that the colloid contained only W2.00 and W nanoparticles. Relative to industrial EDM applications for nano-W colloid preparation, the ee-micro-EDM system boasts a lower cost and smaller size, and produces nano-W colloids with superior performance. These advantages contribute to the competitiveness of the electrical spark discharge method in the preparation of high-quality nano-W colloids.

Reduction of Friction Using Microabrasive Air Jet Machining

“…Bhattacharyya [ 9 ] proposed a design for the development of a setup of an electrochemical microscopic recruitment (EMM) system with a tool diameter of about 150–200 µm, which was a challenge in the field of micromachining, especially in the machining of microparts in the electronics and precision industries. Chang [ 10 ] reported on an energy-enhanced (ee) microelectric discharge machining (EDM) system for the fabrication of nanotungsten (nano-W) colloids applicable to surface texturing processing. The nano-W colloid produced by the ee micro-EDM system has a particle size of about 11–12 nm, and this technology was proposed as an advanced technology capable of producing high-quality nano-W colloids.…”

Plasma-based one-step synthesis of tungsten oxide nanoparticles in short time

“…The band gap of nanoparticles was measured to be 2.92 eV. Chang et al 18 produced nano-tungsten colloids with an average particle size of 164.9 nm, absorbance wavelength of 315 nm, potential of − 64.9 mV, and a minimum particle size of 11 nm using a spark discharge system in deionized water.…”