Simulation and experimental investigation on micro electrochemical drilling of micro-holes with ultra short pulse voltage

Abstract

This paper introduces an electrochemical drilling process which is efficient in fabricating micro-holes, in order to study the influences of ultra short pulse voltage and high speed spiral micro electrode on the machining accuracy and machining efficiency of micro electrochemical drilling, the simulation of the gap electric field and the gap flow field are carried out. Firstly, the model of ultra short pulse gap electric field was established, by simulating the process of the drilling, the shape change of the anode workpiece surface was analysed and predicted with the ultra short pulse voltage. The results show that the ultra short pulse voltage can greatly improve the machining accuracy. Secondly, by using CFX to simulate the gap flow field, with the increase of the electrode rotating speed, the gas film generated with good insulation effect can greatly reduce the taper of the micro-holes. Finally, the simulation results above were verified by the experiments, a series of micro-holes was fabricated successfully; the diameter of the micro-holes was less than 200 μm, which proved that the micro electrochemical drilling for fabricating micro-holes has a widespread application prospect.

Analysis on Machining Performance of Nickel-Base Superalloy by Electrochemical Micro-milling with High-Speed Spiral Electrode

“…The turbulent energy transport equation in the direction of X is as follows [19]:∂(ρk)∂t+∂(ρkui)∂xi=∂∂xj[(μ+μtσk)∂k∂xj]+μt(∂ui∂xj+∂uj∂xi)∂ui∂xj−ρCDk32ε where, k is the turbulent energy, ρ is the electrolyte density, xi, xj is the form of a tensor symbol in the x direction, u is the velocity, ui and uj…”

“…The turbulence model selected in this paper is the Standard k - ε model, and the transport equation corresponding to the k - ε model [19,20] is:∂(ρk)∂t+∂(ρkui)∂xi=∂∂xj[(μ+μtσk)∂k∂xj]+Gk+Gb−ρε−YM ∂(ρε)∂t+∂(ρεui)∂xi=∂∂xj[(μ+μtσε)∂ε∂xj]+C1εεk(Gk+C3εGb)−C2ερ…”